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| TETSUKA, Masafumi; NANCARROW, Colin. D.; 手塚, 雅文. |
| Cyclic Merino ewes were immunized three times against 5α−androstane-3α,17β-diol (3α-diol) at three week intervals (weeks 0,3 and 6). After the third immunization, estrous cycles were synchronized by a series of PG injections and intensive blood samples were obtained for gonadotropin analyses during the mid-luteal phase and during the early follicular phase. Ovulation rates were determined after each immunization and subsequent cloprostenol (PG)-induced luteolysis (weeks 3, 6, 8 and 11). After the second immunization, daily blood samples were obtained and concentrations of plasma progesterone (P) were measured. Immunization against 3α-diol significantly increased the ovulation rate after the second and third immunizations and at week 10 (P<0.01,... |
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Palavras-chave: Ovulation rate; Sheep; Immunization; 5a-reduced androgen. |
| Ano: 2001 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3033 |
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| 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... |
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Palavras-chave: Antarctic minke whale; Areola; Balaenoptera bonaerensis; Placenta; Steroidogenesis. |
| Ano: 2014 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3861 |
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| OKAWARA, Sumika; HAMANO, Seizo; TETSUKA, Masafumi; 手塚, 雅文. |
| Glycerol plays multi-functional roles in cellular physiology. Other than forming the backbone molecule for glycerophospholipid and triglyceride (TG), glycerol acts as an energy substrate for glycolysis. Spermatozoa are known to utilize glycerol for energy production, but there are no reports of this in oocytes. In this study, the value of glycerol as an energy substrate for bovine oocyte maturation (Exp. 1) and the gene expression of glycerol kinase (GK), an enzyme crucial for cellular glycerol utilization, in bovine oocytes and early embryos (Exp. 2) were examined. In Exp. 1, in vitro maturation (IVM) was conducted using synthetic oviduct fluid supplemented with/without glucose (1.5 mM) and/or glycerol (1.0 mM), and maturation rate, degree of cumulus... |
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Palavras-chave: Bovine; Embryo; Glycerol; Glycerol kinase (GK); Oocyte maturation. |
| Ano: 2009 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2829 |
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| 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<1, ≥8.5 mm) and small follicles (E/P<1, <8.5 mm). E-A follicles were easily identified as E2-rich dominant follicles and were further classified... |
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Palavras-chave: Bovine; Follicular fluid; Follicle classification; Glucose; Lactate; Steroid. |
| Ano: 2009 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2828 |
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| 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... |
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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 |
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| 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... |
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Palavras-chave: Bovine; Cortisol; 11β-HSD; Follicle; Glucocorticoid receptor; MRNA. |
| Ano: 2010 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2810 |
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| MURASAWA, Maya; TAKAHASHI, Tsuyoshi; NISHIMOTO, Hiromi; YAMAMOTO, Sawa; HAMANO, Seizo; TETSUKA, Masafumi; 手塚, 雅文. |
| The size of the ovary varies substantially among cattle. This variation may influence the potential of the ovary to produce follicles. In the present study, we examined whether a relationship exists between the weight of the ovary and the number of antral follicles ≥1 mm. Paired ovaries were obtained from Holstein × Japanese Black F1 heifers. Follicles were classified into three size categories (small: 1.0 - < 5.0 mm, medium: 5.0 - < 8.5 mm and large: ≥ 8.5 mm), and the number of follicles in each category was recorded. Large variations in the weight of ovaries and the number of follicles were observed among animals. Significant positive correlations (r≥0.4, P<0.001) were found between the weight of intact ovaries and the number of follicles in... |
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Palavras-chave: Cattle; Follicular development; Follicular population; Ovarian weight. |
| Ano: 2005 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3035 |
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| 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... |
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Palavras-chave: Antarctic minke whale; Balaenoptera bonaerensis; Morphology; Placenta; Steroidogenesis. |
| Ano: 2013 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3862 |
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| TETSUKA, Masafumi; ASADA, Masatsugu; MOGOE, Toshihiro; FUKUI, Yutaka; ISHIKAWA, Hajime; OHSUMI, Seiji; 手塚, 雅文; 福井, 豊. |
| This study describes the morphological and morphometrical changes associated with prepubertal ovarian development in the Antarctic minke whale (Balaenoptera bonaerensis). Ovaries were harvested from 94 immature minke whales caught in the Antarctic Ocean during the summer feeding season (December-March). Notable differences in ovarian size and morphology were found among animals. Up to 10 folds difference in ovarian weight was found among prepubertal whales of similar body size. During the prepubertal period, ovaries grew slowly and approximately doubled their weight. The morphologies of right and left ovaries were almost identical while the growth of the ovary appears to occur preferentially on the right side. The most striking morphological feature was... |
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Palavras-chave: Whale; Minke whale; Ovarian development. |
| Ano: 2004 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3034 |
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