Consulta: creatorFacets:"HAYASHI, Ken-Go"
Registros recuperados: 5
Data/hora: 05/06/2024 18:23:25

Expression of mRNA for the Angiopoietin-Tie System in Granulosa Cells during Follicular Development in Cows
Provedor de dados: 19
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: 19
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

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: 19
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

Effect of the Dominant Follicle Aspiration before or after Luteinizing Hormone Surge on the Corpus Luteum Formation in the Cow
Provedor de dados: 19
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

Changes in Follicular Vascularity during the First Follicular Wave in Lactating Cows
Provedor de dados: 19
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