Consulta: creatorFacets:"MIYAMOTO, Akio"
Registros recuperados: 42
Data/hora: 10/06/2024 18:03:51

Relationship between the degree of insulin resistance during late gestation and postpartum performance in dairy cows and factors that affect growth and metabolic status of their calves
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: KAWASHIMA, Chiho; MUNAKATA, Megumi; SHIMIZU, Takashi; MIYAMOTO, Akio; KIDA, Katsuya; MATSUI, Motozumi; 川島, 千帆; 清水, 隆; 宮本, 明夫; 木田, 克弥; 松井, 基純.
This study aimed to investigate the effects of insulin resistance (IR) during the close-up dry period on the metabolic status and performance of dairy cows as well as to determine the effects on body weight (BW) and metabolic status of their calves. An insulin tolerance test (ITT) was conducted by administering 0.05 IU/kg BW of insulin to 34 multiparous Holstein cows at 3 weeks prepartum. Blood samples were collected at 0, 30, 45 and 60 min after insulin injection, and cows were divided into two groups based on the time required for glucose to reach the minimum levels [non-IR (NIR), 45 min (n=28); and IR, 60 min (n=6)]. Blood or milk sampling and body condition score (BCS) estimation were performed twice weekly during the experimental period. Blood samples...
Palavras-chave: Dairy cow; Dry period; Insulin tolerance test; Metabolic status; Postpartum performance.
Ano: 2016
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4363

The Effect of Single Nucleotide Polymorphisms in the Tumor Necrosis Factor-α Gene on Reproductive Performance and Immune Function in Dairy Cattle
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: KAWASAKI, Yurie; AOKI, Yuka; MAGATA, Fumie; MIYAMOTO, Akio; KAWASHIMA, Chiho; HOJO, Takuo; OKUDA, Kiyoshi; SHIRASUNA, Koumei; SHIMIZU, Takashi; 宮本, 明夫; 清水, 隆.
The present study aimed to assess the effect of polymorphisms in the tumor necrosis factor α (TNF-α) promoter (A/A, A/G and G/G) and exons (T/T, T/C and C/C) on immune function and reproductive performance in dairy cows. The occurrence of the first postpartum ovulation within 3 weeks in the cows with the TNF-α promoter A/G and G/G genotypes was higher than in the A/A group. Among the different TNF-α exon genotypes, the occurrence of early first postpartum ovulation was higher in the T/C and C/C genotype groups than in the T/T group. Single nucleotide polymorphisms (SNPs) in the TNF-α gene did not affect the rate of artificial insemination (AI) or duration from parturition to next conception (days open). The apoptosis rate of polymorphonuclear leukocytes...
Palavras-chave: Cattle; Immune function; Polymorphism; Reproductive performance; Tumor necrosis factor α (TNF-α).
Ano: 2014
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3934

Comparison of Bacterial Endotoxin Lipopolysaccharide Concentrations in the Blood, Ovarian Follicular Fluid and Uterine Fluid: A Clinical Case of Bovine Metritis
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: MAGATA, Fumie; ISHIDA, Yoshikazu; MIYAMOTO, Akio; FURUOKA, Hidefumi; INOKUMA, Hisashi; SHIMIZU, Takashi; 宮本, 明夫; 古岡, 秀文; 猪熊, 壽; 清水, 隆.
We investigated the concentration of the bacterial endotoxin lipopolysaccharide (LPS) in the blood, ovarian follicular fluid and uterine fluid of a clinical case of bovine metritis. A 2-year-old lactating Holstein cow exhibited continuous fever &gt;39.5°C for more than 2 weeks after normal calving. The cow produced a fetid, watery, red-brown uterine discharge from the vagina and was diagnosed with metritis. The LPS concentrations in plasma and uterine fluid were 0.94 and 6.34 endotoxin units (EU)/ml, respectively. One of seven follicles showed an extremely high level of LPS (12.40 EU/ml) compared to the other follicles (0.62–0.97 EU/ml). These results might suggest the presence of high concentration of LPS in follicles in cows with postpartum metritis.
Palavras-chave: Dairy cow; Follicle; Lipopolysaccharide; Metritis.
Ano: 2015
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4043

Relationships Between the First Ovulation Postpartum and Polymorphism in Genes Relating to Function of Immunity, Metabolism and Reproduction in High-producing Dairy Cows
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: SHIRASUNA, Koumei; KAWASHIMA, Chiho; MURAYAMA, Chiaki; AOKI, Yuka; MASUDA, Yutaka; KIDA, Katsuya; MATSUI, Motozumi; SHIMIZU, Takashi; MIYAMOTO, Akio; 白砂, 孔明; 川島, 千帆; 増田, 豊; 木田, 克弥; 松井, 基純; 清水, 隆; 宮本, 明夫.
The decrease in fertility and conception rates of high-producing dairy cows is one of the major negative impacts for today's producers. The recovery of ovarian activity postpartum is affected by the status of immunity, metabolism and reproduction and plays a critical role in subsequent fertility after parturition in the cow. In the present study we investigated the relationships between polymorphisms in genes relating to the above functions and the first postpartum ovulation as a marker of the recovery of ovarian function in the cow. In immune function related-factors, the occurrence of first postpartum ovulation within 3 weeks in the C/C genotypes of tumor necrosis factor α (TNFα) exon (55.4%) and the A/G genotypes of TNFα promoter (55.4%) was...
Palavras-chave: Cow; Ovulation; Polymorphism; Tumor necrosis factor α (TNFα).
Ano: 2011
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2990

Differential Effect of Follicle-Stimulating Hormone and Estradiol on Expressions of Vascular Endothelial Growth Factor (VEGF) 120, VEGF164 and Their Receptors in Bovine Granulosa Cells
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: SHIMIZU, Takashi; JAYAWARDANA, Barana C.; TETSUKA, Masafumi; MIYAMOTO, Akio; 清水, 隆; 手塚, 雅文; 宮本, 明夫.
Vascular endothelial growth factor (VEGF) isoforms (VEGF 120 and VEGF 164) secreted by granulosa cells are involved in thecal angiogenesis during follicular development in the bovine ovary. However, whether the transcript of the VEGF120 and VEGF164 isoforms differs during follicular development in the ovary is still unknown. We first examined the gene expression of VEGF120, VEGF164, fms-like tyrosine kinase (Flt-1), and fetal liver kinase (Flk-1) in the granulosa cells (GCs) and theca cells (TCs) of pre-selection and post-selection follicles (PRF and POF respectively) from the bovine ovary. Then we examined the effects of FSH and estradiol (E2) on these factors in cultured bovine GCs. Messenger RNA (mRNA) expression was quantified using real-time PCR...
Palavras-chave: Estradiol; Fetal liver kinase (Flk-1); Fms-like tyrosine kinase (Flt-1); Follicle-stimulating hormone (FSH); Granulosa cell; Vascular Endothelial Growth factor (VEGF).
Ano: 2007
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4057

Gene Expression of 11β-HSD and Glucocorticoid Receptor in the Bovine (Bos taurus) Follicle During Follicular Maturation and Atresia : The Role of Follicular Stimulating Hormone
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: TETSUKA, Masafumi; NISHIMOTO, Hiromi; MIYAMOTO, Akio; OKUDA, Kiyoshi; HAMANO, Seizo; 手塚, 雅文; 宮本, 明夫.
Glucocorticoids modulate ovarian function in cattle. However, their regulatory mechanisms have not been fully elucidated. In the present study, we examined gene expression of two glucocorticoid-metabolizing enzymes, a bidirectional 11β-HSD type 1 (11HSD1) and a dehydrogenase 11β-HSD type 2 (11HSD2), and glucocorticoid receptor (GR) in bovine follicles during follicular maturation and atresia. Granulosa cells (GCs) and theca interna layers (TIs) were harvested from follicles classified as small growing, dominant, preovulatory, early atretic and late atretic follicles. The expression levels of 11HSD1, 11HSD2 and GR mRNA were quantified by real-time PCR. In the healthy follicles, expression of 11HSD1 mRNA increased as follicles matured, both in GCs and TIs. A...
Palavras-chave: Bovine; Cortisol; 11β-HSD; Follicle; Glucocorticoid receptor; MRNA.
Ano: 2010
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2810

N-acetylglucosaminyltransferase I Activity of Bovine Oviduct Epithelial Cells: Stimulation by Luteinizing Hormone, Vascular Endothelial Growth Factor and Tumor Necrosis Factor α
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: NOZAKI, Hirofumi; WIJAYAGUNAWARDANE, Missaka P.B.; KODITUWAKKU, Suranga P.; YOSHIDA, Takashi; NAKAMURA, Tadashi; ARAI, Ikichi; URASHIMA, Tadasu; MIYAMOTO, Akio; 中村, 正; 浦島, 匡; 宮本, 明夫.
N-acetylglucosaminyltransferase I (GnT I; EC 2.4.1.101), which catalyzes the first step in the conversion of oligomannose to complex or hybrid N-glycans of glycoproteins, was found in media cultured with bovine oviduct epithelial cells (BOEC) obtained from non-pregnant cows during the follicular phase. Combined treatment with specific hormones increased GnT I release from BOEC. Luteinizing hormone (LH; 10 ng/ml) alone slightly, but together with 17β-estradiol (E2; 1 ng/ml), synergistically increased GnT I activity. Vascular endothelial growth factor (VEGF) and tumor necrosis factor (TNF) α, which have been shown to have their highest activities in the bovine oviduct during the periovulatory period, also increased in GnT I activity. This study provides the...
Palavras-chave: Bovine; Luteinizing hormone (LH); N-acetylglucosaminyltransferase I; Oviduct; Tumor necrosis factor (TNF) α; Vascular endothelial growth factor (VEGF).
Ano: 2005
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2978

Structure and Steroidogenesis of the Placenta in the Antarctic Minke Whale (Balaenoptera bonaerensis
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: SASAKI, Motoki; AMANO, Yoko; HAYAKAWA, Daisuke; TSUBOTA, Toshio; ISHIKAWA, Hajime; MOGOE, Toshihiro; OHSUMI, Seiji; TETSUKA, Masafumi; MIYAMOTO, Akio; FUKUI, Yutaka; BUDIPITOJO, Teguh; KITAMURA, Nobuo; 佐々木, 基樹; 手塚, 雅文; 宮本, 明夫; 北村, 延夫.
There are few reports describing the structure and function of the whale placenta with the advance of pregnancy. In this study, therefore, the placenta and nonpregnant uterus of the Antarctic minke whale were observed morphologically and immunohistochemically. Placentas and nonpregnant uteri were collected from the 15th, 16th and 18th Japanese Whale Research Programme with Special Permit in the Antarctic (JARPA) and 1st JARPA II organized by the Institute of Cetacean Research in Tokyo, Japan. In the macro- and microscopic observations, the placenta of the Antarctic minke whale was a diffuse and epitheliochorial placenta. The chorion was interdigitated to the endometrium by primary, secondary and tertiary villi, which contained no specialized trophoblast...
Palavras-chave: Antarctic minke whale; Balaenoptera bonaerensis; Morphology; Placenta; Steroidogenesis.
Ano: 2013
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3862

Tumor Necrosis Factor α System in the Bovine Oviduct: A Possible Mechanism for Embryo Transport
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: WIJAYAGUNAWARDANE, Missaka Priyadarsana Bandara; MIYAMOTO, Akio; 宮本, 明夫.
JSAR Outstanding Presentation Award
Palavras-chave: Cow; Oviductal contraction; Tumor necrosis factor α; Gamete/embryo transport.
Ano: 2004
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2976

Lipopolysaccharide (LPS) Inhibits Steroid Production in Theca Cells of Bovine Follicles In Vitro: Distinct Effect of LPS on Theca Cell Function in Pre- and Post-selection Follicles
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: MAGATA, Fumie; HORIUCHI, Maya; MIYAMOTO, Akio; SHIMIZU, Takashi; 宮本, 明夫; 清水, 隆.
In postpartum dairy cows, lipopolysaccharide (LPS) derived from gram-negative bacteria such as Escherichia coli causes uterine inflammation and leads to ovarian dysfunction. The aim of this study was to determine the effect of LPS on steroid production in bovine theca cells at different stages of follicular development. Theca cells isolated from pre- and post-selection follicles (PRFs, &lt;8.5 mm in diameter, and POFs, &gt;8.5 mm in diameter, respectively) of bovine ovaries were exposed to LPS under luteinizing hormone (LH) conditions, estradiol (E2) conditions or both conditions in vitro. Bovine theca cells expressed the LPS receptor gene complex: Toll-like receptor 4 (TLR4), CD14 and MD2. LPS suppressed progesterone (P4) and androstenedione (A4)...
Palavras-chave: Androstenedione; Dairy cow; Lipopolysaccharide; Progesterone; Theca cells.
Ano: 2014
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3935

Expression of mRNA for the Angiopoietin-Tie System in Granulosa Cells during Follicular Development in Cows
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: HAYASHI, Ken-Go; BERISHA, Bajram; MATSUI, Motozumi; SCHAMS, Dieter; MIYAMOTO, Akio; 松井, 基純; 宮本, 明夫.
Recent findings indicate that the changing profile of angiopoietins (ANPT) and their receptor Tie2 are closely associated with development and regression of the vascular network in the cyclic ovary. We previously reported that mRNA expression for the ANPT-Tie system in theca interna changes during bovine follicular development and atresia, and both ANPTs affect steroidogenesis in the preovulatory follicle. The aim of this study was to investigate mRNA expression for ANPT1, ANPT-2 and Tie2 in granulosa cells (GC) during follicular development in the cow. Bovine follicles were classified according to the estradiol-17β (E2) concentration in follicular fluid (FF) as follows: (1) E2&lt;0.5, (2) 0.5&lt;E2&lt;5, (3) 5&lt;E2&lt;20, (4) 20&lt;E2&lt;180 and (5)...
Palavras-chave: Follicular development; Angiopoietin-Tie system; Granulosa cell; Cow.
Ano: 2004
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2975

Changes in Plasma Metabolic Hormone Concentrations During the Ovarian Cycles of Japanese Black and Holstein Cattle
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: KAWASHIMA, Chiho; KIDA, Katsuya; HAYASHI, Ken-Go; AMAYA MONTOYA, Carlos; KANEKO, Etsushi; MATSUNAGA, Nobuyoshi; SHIMIZU, Takashi; MATSUI, Motozumi; MIYAKE, Yoh-Ichi; SCHAMS, Dieter; MIYAMOTO, Akio; 川島, 千帆; 木田, 克弥; 清水, 隆; 松井, 基純; 三宅, 陽一; 宮本, 明夫.
The aim of the present study was to investigate the changing profiles of plasma metabolic hormones during the ovarian cycles of beef and dairy cattle. We used 16 non-pregnant, non-lactating Japanese Black beef cattle (6 heifers and 10 cows; parity=2.3 ± 0.8) and 12 multiparous Holstein dairy cows (parity=3.0 ± 0.3). Blood samples for hormonal analysis (growth hormone, GH; insulin-like growth factor-I, IGF-1; insulin; and progesterone, P4) were obtained twice weekly for 40 days before artificial insemination for Japanese Black cattle and from 50 to 100 days postpartum for Holstein cows. Luteal phases were considered normal if the P4 concentrations for at least 3 time points over the course of 7 days remained above 1 ng/ml and at least 2 of the time points...
Palavras-chave: Cattle; Insulin-like growth factor-I; Ovarian cycle; Progesterone.
Ano: 2007
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2984

Slow recovery of blood glucose in the insulin tolerance test during the prepartum transition period negatively impacts the nutritional status and reproductive performance postpartum of dairy cows.
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: LEE, Hsu-Hsun; KIDA, Katsuya; MIURA, Ryotaro; INOKUMA, Hisashi; MIYAMOTO, Akio; KAWASHIMA, Chiho; HANEDA, Shingo; MIYAKE, Yoh-Ichi; MATSUI, Motozumi; 猪熊, 壽; 宮本, 明夫; 川島, 千帆; 羽田, 真悟; 松井, 基純.
In peripartum dairy cows, insulin resistance (IR) increases to adjust the direction of energy to lactation after calving. To investigate the effect of prepartum IR on postpartum reproductive performance, the insulin tolerance test (ITT) was applied to 15 cows at 3 weeks (Pre21) and 10 days (Pre10) before the predicted calving date. Blood glucose area under the curve (AUCglu) within 120 min after administration of 0.05 IU/kg-BW insulin was calculated. The occurrence of first ovulation, days to first artificial insemination (AI) and first AI conception rate were recorded. Nutritional status postpartum was evaluated by blood chemical analysis. Based on AUCglu changes from Pre21 to Pre10, cows were classified into either the AUC-up group (AUCglu increase, n=5)...
Palavras-chave: Dairy cows; Glucose metabolism; Insulin tolerance test; Reproductive performance; Transition period.
Ano: 2012
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4129

Relationship between Peripartal Plasma Oxytocin and Prostaglandin F2α Metabolite and Placental Expulsion Time in Heavy Draft Mares
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: ISHII, Mitsuo; KOBAYASHI, Syuichi; ACOSTA, Tomas J.; MIKI, Wataru; YAMANOI, Takahiro; MATSUI, Motozumi; MIYAKE, Yoh-Ichi; MIYAMOTO, Akio; 石井, 三都夫; 松井, 基純; 三宅, 陽一; 宮本, 明夫.
The aim of this study was to clarify the relationship between circulating oxytocin (OT) and PGF2α metabolite (PGFM) in mares at the third stage of labor and placental expulsion time in order to investigate a cause of retained placenta of which the incidence increase in a heavy draft mare. Blood was sampled every 5 min from foaling to expulsion of the placenta in 18 heavy draft mares to evaluate circulating OT and PGFM. The relationships between OT and PGFM concentration and recorded placental expulsion times were investigated. The results were as follows (1) The highest level of OT concentration was observed close to foaling in 15 mares. (2) The OT concentrations close to foaling were variable with a large difference from the lowest concentration, 22.1...
Palavras-chave: Heavy draft mare; Oxytocin; 15-keto-dihydro prostaglandin F2α (PGFM); Placental expulsion.
Ano: 2008
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3089

Areolae of the Placenta in the Antarctic Minke Whale (Balaenoptera bonaerensis)
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: SASAKI, Motoki; AMANO, Yoko; HAYAKAWA, Daisuke; TSUBOTA, Toshio; ISHIKAWA, Hajime; MOGOE, Toshihiro; OHSUMI, Seiji; TETSUKA, Masafumi; MIYAMOTO, Akio; FUKUI, Yutaka; BUDIPITOJO, Teguh; KITAMURA, Nobuo; 佐々木, 基樹; 手塚, 雅文; 宮本, 明夫; 北村, 延夫.
In this study, we examined the existence and structure of areolae and the steroidogenesis of areolar trophoblast cells in the Antarctic minke whale placenta morphologically and immunohistochemically. Placentas were collected from the 15th, 16th and 18th Japanese Whale Research Program under Special Permit in the Antarctic (JARPA) and 1st JARPA II organized by the Institute of Cetacean Research in Tokyo, Japan. The opening and cavity of fetal areolae formed by taller columnar trophoblast cells (areolar trophoblast cells) with long microvilli and a bright cytoplasm, as compared with the trophoblast cells of the chorionic villi interdigitating with the endometrial crypts, were recognized in observations of serial sections. The opening of the areolar cavity...
Palavras-chave: Antarctic minke whale; Areola; Balaenoptera bonaerensis; Placenta; Steroidogenesis.
Ano: 2014
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3861

Gene Expressions in the Persistent Corpus Luteum of Postpartum Dairy Cows: Distinct Profiles from the Corpora Lutea of the Estrous Cycle and Pregnancy
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: MAGATA, Fumie; SHIRASUNA, Koumei; STRÜVE, Klaas; HERZOG, Kathrin; SHIMIZU, Takashi; BOLLWEIN, Heinrich; MIYAMOTO, Akio; 清水, 隆; 宮本, 明夫.
Persistence of the corpus luteum (CL) in cattle usually occurs during the puerperium and is associated with interference of prostaglandin (PG) F2α release from the uterus. The objective of the present study was to determine for the first time the gene expressions in the persistent CL compared with the CL of pregnancy and cyclic CL. Three types of CL biopsy samples were collected from 32 lactating Holstein cows: (1) CL persisting for 29 to 33 days after the first ovulation postpartum (persistent CL, n=9), (2) CL between days 29 and 33 of early pregnancy (CL of pregnancy, n=8) and (3) CL between days 10 and 13 of the estrous cycle (cyclic CL, n=27). mRNA expression of 2',5'-oligoadenylate synthetase-1 was upregulated only in the CL of pregnancy, confirming...
Palavras-chave: Dairy cow; Early pregnancy; Persistent corpus luteum; MRNA expression.
Ano: 2012
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3938

Influence of hepatic load from far-off dry period to early postpartum period on the first postpartum ovulation and accompanying subsequent fertility in dairy cows
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: KAWASHIMA, Chiho; ITO, Nozomi; NAGASHIMA, Shuntarou; MATSUI, Motozumi; SAWADA, Kumiko; SCHWEIGERT, Florian J.; MIYAMOTO, Akio; KIDA, Katsuya; 川島, 千帆; 松井, 基純; 宮本, 明夫; 木田, 克弥.
The aim of the present study was to investigate nutritional and metabolic parameters during the dry and early postpartum periods of ovulatory and anovulatory cows, as well as their postpartum reproductive performance. Blood samples from 20 multiparous Holstein cows were collected once a week from the far-off dry period to 3 weeks postpartum. Early postpartum (0–3 weeks) ovulation was confirmed using plasma progesterone concentration profiles, and cows were considered ovulatory if they had resumed luteal activity by this point (n = 9), whereas cows that had not were considered anovulatory (n = 11). Data from the ovulatory and anovulatory cows were analyzed separately for the far-off dry period (7–4 weeks prepartum), the close-up dry period (3–1 weeks...
Palavras-chave: Dairy cow; First ovulation; Hepatic enzyme; Liver function; Reproductive performance.
Ano: 2016
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4308

Changes in the Messenger RNA Expressions of the Endothelin-1 and Angiotensin Systems in Mature Follicles of the Superovulated Bovine Ovary
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: SHIMIZU, Takashi; BERISHA, Bajram; SCHAMS, Dieter; MIYAMOTO, Akio; 清水, 隆; 宮本, 明夫.
The aim of the present study was to examine the messenger RNA expressions of the endothelin and angiotensin systems during the periovulatory phase in gonadotrophin releasing hormone (GnRH)-treated cows. Ovaries were collected by transvaginal ovariectomy (n=5 cows/group), and the follicles (n=5, one follicle/cow) were classified into the following groups: before GnRH administration (control, before LH surge), 3-5 h after GnRH (during LH surge), 10 h after GnRH; 20 h after GnRH, 25 h after GnRH (peri-ovulation), and early corpus luteum (CL) (Days 2-3). Expression of mRNA was investigated using quantitative real-time PCR. The expression of angiotensin converting enzyme (ACE) mRNA significantly decreased immediately after onset of the LH surge and remained at...
Palavras-chave: Angiotensin; Bovine; Endothelin-1; Gonadotrophin releasing hormone (GnRH); Ovulation.
Ano: 2007
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2987

In Vivo Evidence that Local Cortisol Production Increases in the Preovulatory Follicle of the Cow
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: ACOSTA, Tomas J.; TETSUKA, Masa; MATSUI, Motozumi; SHIMIZU, Takashi; BERISHA, Bajram; SCHAMS, Dieter; MIYAMOTO, Akio; 松井, 基純; 清水, 隆; 宮本, 明夫.
The aim of the present in vivo study was to monitor real-time fluctuations of cortisol (Cr) in the wall of preovulatory follicles using a microdialysis system (MDS) implanted in the theca layer as well as changes in ovarian venous plasma (OVP) and jugular venous plasma (JVP). Seven cows were superovulated using FSH and prostaglandin F2α injections. Dialysis capillary membranes were surgically implanted into the theca layer of mature follicles and connected to a microdialysis system. Fractions of the perfusates were collected from Day -1 (Day 0=LH surge) to Day 3. No difference in the concentrations of Cr between JVP and OVP was detected throughout the experiment. Circulating concentrations of Cr ranged from 20 to 35 ng/ml 8 h after surgery in ovulatory and...
Palavras-chave: Bovine; Cortisol; Follicle; Ovary; Ovulation.
Ano: 2005
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2980

Prostaglandin F2α Differentially Affects mRNA Expression Relating to Angiogenesis，Vasoactivation and Prostaglandins in the Early and Mid Corpus Luteum in the Cow
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: SHIRASUNA, Koumei; SASAHARA, Kiemi; MATSUI, Motozumi; SHIMIZU, Takashi; MIYAMOTO, Akio; 白砂, 孔明; 松井, 基純; 清水, 隆; 宮本, 明夫.
Administration of prostaglandin (PG) F2α in cattle during the mid-luteal phase (Days 8-12 of the estrous cycle) drastically reduces the plasma progesterone concentrations and the volume of the corpus luteum (CL). However, PGF2α does not induce luteolysis during the early luteal phase (up to Day 5 of the estrous cycle). To characterize the possible distinct difference in acute response to a luteolytic dose of PGF2α administration, we determined various mRNA expressions in the early and mid CL relating to angiogenesis, vasoactivation and PG-related factors at 30 min after PGF2α injection in cyclic cows. The experiments were conducted on Day 4 (early CL) and Days 10-12 (mid CL). Cows were either injected with 500 μg PGF2α analogue or saline as the control...
Palavras-chave: Corpus luteum; Cow; Luteolysis; Prostaglandin F2α.
Ano: 2010
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2812

Genital  Blood Flow and Endometrial Gene Expression During the Preovulatory Period after Prostaglandin F2α-Induced Luteolysis in Different Luteal Phases in Cows
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: JORDAN, Anne; HERZOG, Kathrin; ULBRICH, Susanne E; BEINDORFF, Nicola; HONNENS, Änne; KRÜGER, Lars; MIYAMOTO, Akio; BOLLWEIN, Heinrich; 宮本, 明夫.
The aim of this study was to examine the hypothesis that follicular and uterine perfusion as well as endometrial gene expression during the ovulatory period differs after induction of luteolysis during the 1st follicular wave compared with the 2nd wave or in intact cycle. Nine healthy non-lactating Holstein-Friesian cows were examined during three estrous cycles. A prostaglandin F2α analogue (PGF) was administered randomly either on Day 7 (1st wave cycle) or Day 11 (2nd wave cycle) after detection of ovulation (=Day 1). No hormonal treatment was used in the intact cycle with spontaneous ovulation. Transrectal Doppler sonography was conducted daily after PGF injection and in the intact cycle beginning on Day 18 of the estrous cycle until ovulation....
Palavras-chave: Blood flow; Cow; Endometrial receptors; Follicle; Prostaglandin F2α.
Ano: 2009
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2813

An Acute-phase Protein as a Regulator of Sperm Survival in the Bovine Oviduct: Alpha 1-acid-glycoprotein Impairs Neutrophil Phagocytosis of Sperm In Vitro
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: LIU, Jinghui; A. MAREY, Mohamed; KOWSAR, Rasoul; HAMBRUCH, Nina; SHIMIZU, Takashi; HANEDA, Shingo; MATSUI, Motozumi; SASAKI, Motoki; HAYAKAWA, Hiroyuki; PFARRER, Christiane; MIYAMOTO, Akio; 羽田, 真悟; 松井, 基純; 佐々木, 基樹; 宮本, 明夫.
We have previously shown that polymorphonuclear neutrophils (PMNs) are present in bovine oviduct fluid under physiological conditions, and that the oviduct provides a microenvironment that protects sperm from phagocytosis by PMNs. Alpha 1-acid glycoprotein (AGP) is a major acute-phase protein produced mainly in the liver that has immunomodulatory functions. AGP mRNA is expressed in extrahepatic organs, such as the lung, kidney, spleen, lymph node, uterus, and ovary. Therefore, in this study, we investigated, 1) the local production of AGP in the bovine oviduct, 2) the effect of AGP on the phagocytic activity of PMNs for sperm and superoxide production and 3) the impact of AGP desialylation on the PMN phagocytosis of sperm. The AGP gene was expressed in...
Palavras-chave: Alpha 1-acid glycoprotein (AGP); Bovine; Oviduct; Phagocytosis; Sperm.
Ano: 2014
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3946

Vascular Changes in the Corpus Luteum During Early pregnancy in the Cow
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: BEINDORFF, Nicola; NAGAI, Kaya; SHIRASUNA, Koumei; HERZOG, Kathrin; HOEFFMANN, Katharina; SASAKI, Motoki; BOLLWEIN, Heinrich; MIYAMOTO, Akio; 佐々木, 基樹; 宮本, 明夫; 白砂, 孔明.
The present study determined vascular changes in the bovine corpus luteum (CL) at Day 16 (early maternal recognition period) and Day 40 in early pregnancy and compared them to the CL from Day 12 and Day 16 of the estrous cycle. The CLs were analyzed in the central and peripheral regions, where site-depending features of vessels and angiogenic factors are evident. The same protein level of the endothelial cell marker von Willebrand factor was retained in the CL from Day 16 of the estrous cycle to Day 40 of early pregnancy. The protein level of pericytes and smooth muscle cells was determined using smooth muscle α-actin; the level decreased at Day 40 of early pregnancy in both regions of the CL. No significant change in the expressions of vascular...
Palavras-chave: Corpus luteum; Cow; Early pregnancy; Endothelial cells.
Ano: 2010
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2811

Intraluteal Release of Prostaglandin F2α and E2 During Corpora Lutea Development in the Cow
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: KOBAYASHI, Shu-ichi; ACOSTA, Tomas J.; HAYASHI, Kanako; BERISHA, Bajram; OZAWA, Takahiro; OHTANI, Masayuki; SCHAMS, Dieter; MIYAMOTO, Akio; 宮本, 明夫.
It is well known that prostaglandin (PG) F2α and PGE2 are actively produced by bovine early corpus luteum (CL) at higher levels than in the CL of later stages. However, there is no in vivo information about the local secretion of PGs within bovine developing CL so far. Thus, the objective of the present study was to determine in detail the real-time changes in PGF2α and PGE2 secretion within developing CL. A microdialysis system (MDS) was surgically implanted into the newly formed CL of 6 cows on Day 3 after GnRH administration (about 1.5 days after ovulation) to induce superovulation following FSH treatment. Both PGF2α and PGE2 release were high during the first 24 h within developing CL but decreased thereafter. These profiles were well reflected in the...
Palavras-chave: PGF2α; PGE2; Developing CL; Cow; In vivo.
Ano: 2002
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2974

Expression of Pin1, a peptidyl-prolyl isomerase, in the ovary of eCG/hCG-treated immature female mice.
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: SHIMIZU, Takashi; AKIYAMA, Hirotada; ABE, Yasuyuki; SASADA, Hiroshi; SATO, Eimei; MIYAMOTO, Akio; UCHIDA, Takafumi; 清水, 隆; 宮本, 明夫.
Protein phosphorylation on certain serine or threonine residues preceding proline (Ser/Thr-Pro) is a pivotal signaling mechanism in diverse cellular processes. Pin1 is a highly conserved enzyme that isomerizes only the phosphorylated Ser/Thr-Pro bonds in certain proteins, thereby inducing conformational changes. Although much protein is phosphorylated in the ovary, the role of Pin1 in the ovary is still unknown. The purpose of this study is to investigate the effects of gonadotropins on protein and mRNA expression of Pin1 in mice ovaries. Quantitative PCR analysis showed that the expression of Pin1 mRNA significantly increased in the ovaries of equine chorionic gonadotropin (eCG)-treated mice compared with those of untreated mice (P&lt;0.05). However,...
Palavras-chave: E2F; Follicle development; Gonadotropin; Ovary; Pin1.
Ano: 2006
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4056

Endothelin-1 downregulates sperm phagocytosis by neutrophils in vitro: a physiological implication in bovine oviduct immunity
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: MAREY, Mohamed Ali; YOUSEF, Mohamed Samy; LIU, Jinghui; MORITA, Kazuhiro; SASAKI, Motoki; HAYAKAWA, Hiroyuki; SHIMIZU, Takashi; ELSHAHAWY, Ibrahim I.; MIYAMOTO, Akio; 佐々木, 基樹; 清水, 隆; 宮本, 明夫.
The oviduct is an active contractile tube that provides the proper environment for sperm transport, capacitation and survival. Oviductal contractions are regulated by autocrine/paracrine secretion of several factors, such as prostaglandins (PGs) and endothelin-1 (EDN-1). We have previously shown that during the preovulatory stage, sperm are exposed to polymorphonuclear neutrophils (PMNs) in the bovine oviduct, and the bovine oviduct epithelial cells (BOECs) secrete molecules including PGE2 that suppress sperm phagocytosis by PMNs in vitro. In this study, we investigated the possible effects of EDN-1 on the phagocytic activity of PMNs toward sperm. The local concentrations of EDN-1 in oviduct fluid and BOEC culture medium ranged from 10–10 to 10–11 M as...
Palavras-chave: Endothelin-1; Oviduct; Phagocytosis; Polymorphonuclear neutrophils (PMN); Sperm.
Ano: 2016
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4310

Classification of Bovine Follicles Based on the Concentrations of Steroids, Glucose and Lactate in Follicular Fluid and the Status of Accompanying Follicles
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: NISHIMOTO, Hiromi; HAMANO, Seizo; HILL, Glen Alan; MIYAMOTO, Akio; TETSUKA, Masafumi; 宮本, 明夫; 手塚, 雅文.
A simple and clear means to identify the physiological status of follicles is essential for study of follicular biology. In the present study, we verified a novel classification procedure based on analysis of the follicular population and glucose concentration in follicular fluid (FF) as an alternative method to classify bovine follicles. Paired ovaries were collected from heifers, and the number of follicles and stage of the CL were recorded. Follicles were initially divided into the following 3 groups according to diameter and the ratio of E2 and P4 (E/P): E2 active (E-A: E/P≥1), E2 inactive (E-I: E/P&lt;1, ≥8.5 mm) and small follicles (E/P&lt;1, &lt;8.5 mm). E-A follicles were easily identified as E2-rich dominant follicles and were further classified...
Palavras-chave: Bovine; Follicular fluid; Follicle classification; Glucose; Lactate; Steroid.
Ano: 2009
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2828

Relative Changes in mRNA Expression of Angiopoietins and Receptors Tie in Bovine Corpus Luteum during Estrous Cycle and Prostaglandin F2α-induced Luteolysis: A Possible Mechanism for the Initiation of Luteal Regression
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: TANAKA, Jun; ACOSTA, Tomas J.; BERISHA, Bajram; TETSUKA, Masa; MATSUI, Motozumi; KOBAYASHI, Shuichi; SCHAMS, Dieter; MIYAMOTO, Akio; 松井, 基純; 宮本, 明夫.
Local angiogenesis and angiolysis in the corpus luteum (CL) relate to the luteal function. Recent studies indicate that angiopoietins (ANPT) and their receptors Tie regulate remodeling of microvasculature. We therefore examined 1) the relative changes in the expression of mRNA for ANPT-1, ANPT-2, Tie1 and Tie2 in bovine CL by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) during the estrous cycle and prostaglandin F2α (PGF2α)-induced luteolysis, and 2) the effect of ANPT-2 on progesterone (P4) release from CL at the late stage of the estrous cycle by an in vitro microdialysis system (MDS). The CLs were classified into 4 stages (early: Day 2-5, n=7, mid: Day 8-12, n=15, late: Day 15-17, n=9, regressing: Day &gt;18, n=19). The...
Palavras-chave: Angiopoietin; Angiolysis; Luteolysis; Corpus luteum; Cow.
Ano: 2004
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2977

Accumulation of Eosinophils in the Infundibulum of the Bovine Oviduct Just after Ovulation
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: KOWSAR, Rasoul; JIEMTAWEEBOON, Sineenard; SHIRASUNA, Koumei; SHIMIZU, Takashi; SASAKI, Motoki; KITAMURA, Nobuo; MIYAMOTO, Akio; 清水, 隆; 佐々木, 基樹; 宮本, 明夫.
This study was to investigate the localization and distribution of eosinophils (EOS) in the bovine oviduct throughout the estrous cycle. Histological studies revealed more abundant EOS in the infundibula of the oviducts ipsilateral to the preovulatory dominant follicle and the ovulated ovary. The number of EOS was higher in the infundibula of the oviducts ipsilateral to the ovulated ovary than those of the oviducts contralateral to the ovulated ovary. The infundibula of the oviducts ipsilateral to the preovulatory dominant follicle had higher number of EOS than those of the oviducts ipsilateral to the mid-cycle corpus luteum. The number of EOS in the isthmus, but not in the ampulla, was higher in the outer layers (tunica muscularis and tunica serosa) than...
Palavras-chave: Bovine; Eosinophil; Oviduct; Ovulation.
Ano: 2014
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3947

Regulation of Innate Immune Function in Bovine Oviduct Epithelial Cells in Culture: The Homeostatic Role of Epithelial Cells in Balancing Th1/Th2 Response
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: KOWSAR, Rasoul; HAMBRUCH, Nina; LIU, Jinghui; SHIMIZU, Takashi; PFARRER, Christiane; MIYAMOTO, Akio; 清水, 隆; 宮本, 明夫.
This study aimed to investigate the role of epithelial cells in regulating innate immunity in bovine oviduct epithelial cell (BOEC) culture. We studied the effect of Escherichia coli lipopolysaccharide (LPS) and its interaction with ovarian steroids, estradiol (E2) and progesterone (P4), and luteinizing hormone (LH) at concentrations observed during the preovulatory period on immune responses in BOEC culture. Immunohistochemistry of oviduct tissue showed intensive expression of Toll-like receptor-4 (TLR-4) and TLR-2 in epithelial cells. A dose of 10 ng/ml LPS stimulated TLR-4, cyclooxygenase-2 (COX-2), nuclear factor kappa B inhibitor A (NFKBIA), interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) expression, indicating an early pro-inflammatory...
Palavras-chave: Bovine oviduct epithelial cell; Ovarian steroids; TLR-4; Th1/Th2 response.
Ano: 2013
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3937

Relationship between the First Ovulation within Three Weeks Postpartum and Subsequent Ovarian Cycles and Fertility in High Producing Dairy Cows
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: KAWASHIMA, Chiho; KANEKO, Etsushi; AMAYA MONTOYA, Carlos; MATSUI, Motozumi; YAMAGISHI, Norio; MATSUNAGA, Nobuyoshi; ISHII, Mitsuo; KIDA, Katsuya; MIYAKE, Yoichi; MIYAMOTO, Akio; 川島, 千帆; 松井, 基純; 石井, 三都夫; 木田, 克弥; 三宅, 陽一; 宮本, 明夫.
The aim of this study was to investigate the relationship between the first ovulation within 3 weeks postpartum and subsequent ovarian cycles and fertility in high producing dairy cattle in Hokkaido, Japan. In Experiment 1, 110 cows (44 primiparous and 66 multiparous) were used to determine the effects of the first ovulation within 3 weeks postpartum on subsequent ovarian cycles. Milk samples were collected twice weekly from 7 to 100 days postpartum. The first ovulation was identified by an increase in milk progesterone (P4) to more than 1 ng/ml within 3 weeks postpartum. The numbers of cows showing ovulation and anovulation within 3 weeks postpartum were 31 (70.5%) and 13 (29.5%) in the primiparous cows and 35 (53.0%) and 31 (47.0%) in the multiparous...
Palavras-chave: Dairy cow; First ovulation; Postpartum; Resumption of ovarian cycle.
Ano: 2006
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/916

A Potential Use of Color Ultrasound as a Tool for Reproductive Management: New Observations Using Color Ultrasound Scanning that were not Possible with Imaging Only in Black and White
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: MIYAMOTO, Akio; SHIRASUNA, Koumei; HAYASHI, Ken-Go; KAMADA, Daichi; KAWASHIMA, Chiho; KANEKO, Etsushi; ACOSTA, Tomas J.; MATSUI, Motozumi; 宮本, 明夫; 白砂, 孔明; 川島, 千帆; 松井, 基純.
Ultrasonography (US) has been applied to the ovary and the uterus of domestic animals from the late 1980s, and established in 1990s as a practical tool for animal production. US made it possible to detect pregnancy at a very early stage and, most importantly, to observe the real-time dynamics of follicular development and hence the discovery of follicular waves. This has greatly contributed to our understanding of ovarian physiology and helped us to develop several "pin-point" protocols for hormonal treatment. While US may not seem to fit preconceived ideas of a "green" technology, it does not contravene environmental priorities, and it is non-invasive ("ethical") and non-hormonal ("clean"). Using the US technology that is now commercially available at a...
Palavras-chave: Color Doppler ultrasound; Blood flow; Ovary; Reproduction; Cow.
Ano: 2006
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2983

Exposure of C57BL/6J Male Mice to an Electric Field Improves Copulation Rates with Superovulated Females
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: HORI, Takuya; YAMSAARD, Thicomeporn; UETA, Yoshiko Yanagimoto; HARAKAWA, Shinji; KANEKO, Etsushi; MIYAMOTO, Akio; XUAN, Xuenan; TOYODA, Yutaka; SUZUKI, Hiroshi; 宮本, 明夫; 玄, 学南; 鈴木, 宏志.
It is well-known that there are considerable strain differences in the relative copulation rates between male and superovulated female mice. In particular, the C57BL/6J strain of mice has a lower rate of successful copulation. We examined the effect of exposure to an electric field on sexual behavior in C57BL/6J male mice. When C57BL/6J males were exposed to a 50 Hz, 45 kV/m electric field for 30 min per day for 11 days and placed in a cage with a superovulated female of the same strain, the successful copulation rates of males was significantly improved compared with unexposed males (P&lt;0.05). These results suggest that the exposure of C57BL/6J male mice to an electric field improves their sub-fertility activity in mating with superovulated females.
Palavras-chave: Mice; Male; Electric field; Copulation; Superovulation; Sexual behavior.
Ano: 2005
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3021

Effect of Suckling on the Reproductive Performance and Metabolic Status of Obese Japanese Black Cattle during the Early Postpartum Period
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: KAWASHIMA, Chiho; KIDA, Katsuya; MATSUHASHI, Miki; MATSUI, Motozumi; SHIMIZU, Takashi; MATSUNAGA, Nobuyoshi; ISHII, Mitsuo; MIYAKE, Yoh-Ichi; MIYAMOTO, Akio; 川島, 千帆; 木田, 克弥; 松井, 基純; 清水, 隆; 石井, 三都夫; 三宅, 陽一; 宮本, 明夫; 松長, 延吉.
The aim of our study was to investigate the effects of suckling on reproductive performance and metabolic status of obese (mean body condition score of more than 4.0 on a scale of 1-5) maternal Japanese Black cows during early postpartum period. We used 7 postpartum Japanese Black cattle. Four cows were suckled ad libitum (suckled) until completion of their first artificial insemination (AI), while 3 cows were not suckled at all because they were separated from their calves immediately after parturition (non-suckled). Body weight and plasma concentrations of metabolites and hormones were measured from wk 1 to 9 postpartum. Ovarian activity was detected using plasma progesterone concentration, and all cows received their first AI after application of the...
Palavras-chave: Japanese Black cattle; Metabolic status; Obesity; Reproductive performance; Suckling.
Ano: 2008
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2991

Changes of Progesterone and Endothelin Concentrations in the Peripheral Plasma of Female Calves and Cycling Cows: Effects of PGF2α Injection
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: OHTANI, Masayuki; OKI, Naoko; TANIMURA, Miyune; KOBAYASHI, Shu-ichi; ACOSTA, Tomas J.; HAYASHI, Kanako; MIYAMOTO, Akio; 宮本, 明夫.
It is well known that an injection of prostaglandin F2α (PGF2α) or its analogue during the mid luteal phase of the estrous cycle induces a rapid decrease in plasma progesterone (P4) concentration, followed by luteolysis in the cow. There is evidence that a potent vasoactive peptide, endothelin-1 (ET-1), is produced in the bovine corpus luteum (CL), and that it is directly involved in luteolysis. We previously found that ET-1 concentrations in the peripheral plasma increase during the period of luteolysis and ovulation in cows. However, it is not clear whether the elevation of peripheral plasma ET-1 concentration observed during luteolysis and ovulation originates exclusively from the ovary and/or CL. Such a profile of plasma ET-1 concentration may be...
Palavras-chave: Endothelin; Progesterone; Plasma; Calves; Cows.
Ano: 2001
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2973

Effect of the Dominant Follicle Aspiration before or after Luteinizing Hormone Surge on the Corpus Luteum Formation in the Cow
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: HAYASHI, Ken-Go; MATSUI, Motozumi; ACOSTA, Tomas J.; KIDA, Katsuya; MIYAMOTO, Akio; 松井, 基純; 木田, 克弥; 宮本, 明夫.
Luteinizing hormone (LH) surge and follicle rupture act as trigger to start corpus luteum (CL) formation. Thus, we aimed to investigate whether a dominant follicle that has not been exposed to an LH surge can become a functional CL. For this purpose, follicular fluid from the dominant follicles (DF) of cows was aspirated before or after a GnRH-induced LH surge, and subsequent CL formation was observed. Holstein cows were divided into four groups as follows: Luteal phase, a DF was aspirated 7 days after GnRH injection; Pre-LH surge, a DF was aspirated 42 h after PGF2α injection during the mid luteal phase; Post-LH surge, a DF was aspirated 24 h after GnRH injection following PGF2α; and Intact follicle, ovulation was induced by GnRH injection after PGF2α....
Palavras-chave: Corpus luteum formation; Cow; Follicle aspiration; LH surge.
Ano: 2006
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2982

Expression of mRNA for Cell Adhesion Molecules in the Bovine Corpus Luteum During the Estrous Cycle and PGF2α-Induced Luteolysis
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: SHIRASUNA, Koumei; WATANABE, Sho; NAGAI, Kaya; SASAHARA, Kiemi; SHIMIZU, Takashi; RICKEN, Albert M.; SPANEL-BOROWSKI, Katharina; MIYAMOTO, Akio; 白砂, 孔明; 清水, 隆; 宮本, 明夫.
Cell-to-cell interaction via cell contact-dependent pathway is essentially important for maintenance and regulation of corpus luteum (CL) integrity and its physiological actions. The objective of the present study was to evaluate the mRNA expression of the cell adhesion molecules (CAMs) that are constituent factors of gap junctions [connexin (Cx) 43] and adherence junctions (VE-, E-, N-cadherin) in two types of endothelial cells from the mid CL and in CL tissue during the estrous cycle and PGF2α-induced luteolysis in the cow. Specific mRNA expression for Cx43 and N-cadherin was detected in cytokeratin-positive (CK+) and cytokeratin-negative (CK-) luteal endothelial cells (EC) and fully luteinized granulosa cells (LGC). E-cadherin mRNA was expressed in...
Palavras-chave: Cadherin; Connexin; Corpus luteum; Cow; Luteolysis.
Ano: 2007
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2988

Distribution of Arteriolovenous Vessels, Capillaries and eNOS Expression in the Bovine Corpus Luteum During the Estrous Cycle : a Possible Implication of Different Sensitivity by Luteal Phase to PGF2α in the Increase of Luteal Blood Flow
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: SHIRASUNA, Koumei; ASAHI, Takayuki; SASAKI, Motoki; SHIMIZU, Takashi; MIYAMOTO, Akio; 白砂, 孔明; 佐々木, 基樹; 清水, 隆; 宮本, 明夫.
We have shown that luteal blood flow increases in the peripheral vasculature of the mature corpus luteum (CL) prior to the onset of luteolysis in response to prostaglandin F2α (PGF2α) in the cow, but this phenomenon does not occur in the early CL. We therefore hypothesize that this acute increase of luteal blood flow occurs by vasodilation of large blood vessels due to local release of nitric oxide (NO). In the present study, we characterized the CL vasculature together with endothelial NO synthase (eNOS) expression during the estrous cycle in the cow. Immunohistochemistry was used to quantify the number of arteriolovenous vessels (surrounded with smooth muscle actin-positive smooth muscle cells), capillaries (with von Willebrand Factor-positive...
Palavras-chave: Blood vessels; Corpus luteum; ENOS; Luteolysis.
Ano: 2010
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2989

Changes in Follicular Vascularity during the First Follicular Wave in Lactating Cows
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: ACOSTA, Tomas J.; HAYASHI, Ken-Go; MATSUI, Motozumi; MIYAMOTO, Akio; 松井, 基純; 宮本, 明夫.
Increase in the blood supply to individual follicles appears to be associated with follicular growth rates and the ability to become the dominant follicle, while reduced thecal vascularity appears to be closely associated with follicular atresia. Therefore, this study aimed to determine the real-time changes in the vascularity of the follicle wall during the first follicular wave in cycling Holstein cows. Normally cycling and lactating cows (n=5) were examined by transrectal color Doppler ultrasonography (the sensitivity for velocity: &gt; 2 mm/sec) to determine the changes in the vasculature of the follicle wall (presence or absence of blood flow) and the diameter of follicles. A new follicular wave and ovulation were induced by GnRH injection at 48 h...
Palavras-chave: Blood flow; Follicular wave; Selection; Deviation; Cow.
Ano: 2005
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2979

Upregulation of interferon-stimulated genes and interleukin-10 in peripheral blood immune cells during early pregnancy in dairy cows.
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: MAGATA, Fumie; SHIRASUNA, Koumei; STRÜVE, Klaas; HERZOG, Kathrin; SHIMIZU, Takashi; BOLLWEIN, Heinrich; MIYAMOTO, Akio; 清水, 隆; 宮本, 明夫.
Persistence of the corpus luteum (CL) in cattle usually occurs during the puerperium and is associated with interference of prostaglandin (PG) F2α release from the uterus. The objective of the present study was to determine for the first time the gene expressions in the persistent CL compared with the CL of pregnancy and cyclic CL. Three types of CL biopsy samples were collected from 32 lactating Holstein cows: (1) CL persisting for 29 to 33 days after the first ovulation postpartum (persistent CL, n=9), (2) CL between days 29 and 33 of early pregnancy (CL of pregnancy, n=8) and (3) CL between days 10 and 13 of the estrous cycle (cyclic CL, n=27). mRNA expression of 2',5'-oligoadenylate synthetase-1 was upregulated only in the CL of pregnancy, confirming...
Palavras-chave: Dairy cow; Early pregnancy; Persistent corpus luteum; MRNA expression.
Ano: 2012
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4039

Nutritional factors that regulate ovulation of the dominant follicle during the first follicular wave postpartum in high-producing dairy cows.
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: KAWASHIMA, Chiho; MATSUI, Motozumi; SHIMIZU, Takashi; KIDA, Katsuya; MIYAMOTO, Akio; 川島, 千帆; 松井, 基純; 清水, 隆; 木田, 克弥; 宮本, 明夫.
During recent decades, milk production per cow has increased drastically due to improved management, nutrition, and genetic selection; however, the reproductive performance of high-producing dairy cows has been declining. One of the factors responsible for this low reproductive performance is negative energy balance (NEB). NEB affects the onset of first ovulation in early postpartum cows. It is generally accepted that early first ovulation positively relates to the resumption of normal ovarian function, first service, and conception rate in dairy cows. Hence, delayed first ovulation has a negative impact on subsequent fertility. The metabolic condition of cows in NEB shifts to catabolic metabolism, which in turn causes increased plasma growth hormone and...
Palavras-chave: Β-Carotene; Dairy cow; First follicular wave postpartum; First ovulation; Metabolic hormone.
Ano: 2012
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4041

Prostaglandin F2α Increases Lipoprotein Utilization for Progesterone in Bovine Early Corpora Lutea In Vitro
Provedor de dados: Obihiro University of Agriculture and Veterinary Medicine Academic Repository (OAK)
Autores: KOBAYASHI, Shu-ichi; MIYAMOTO, Akio; 宮本, 明夫.
Luteal cells utilize lipoproteins (LIPs) for progesterone (P) synthesis. A luteolysin prostaglandin F2α (PGF 2α) has shown to prevent the LIPs utilization for steroidogenesis in bovine midcycle luteal cells. However, a luteolytic injection of PGF2α before Day 5 (Day 0=estrus) can not induce the regression of the corpus luteum (CL). This suggests that the intraluteal mechanism of PGF2 α action on the LIPs utilization in early CL is different from that of the mid luteal stage. Thus, this study aimed to investigate the interaction between PGF2 α and LIPs on the secretion of P and oxytocin (OT) from bovine early CL. An in vitro microdialysis system (MDS) was used as a model. Each bovine early CL (Days 3-4) was implanted with the MDS, and maintained in an organ...
Palavras-chave: PGF2α; Lipoproteins; Early CL; Cow.
Ano: 2000
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2972