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| Shirasuna, Koumei; Watanabe, S.; Oki, N.; Wijayagunawardane, M. P. B.; Matsui, Motozumi; Ohtani, M.; Miyamoto, Akio; 白砂, 孔明; 松井, 基純; 宮本, 明夫. |
| Prostaglandin F-2 alpha (PGF(2 alpha)) is the primary luteolysin in the cow, and luteal endothelin-1 (ET-1) interacts with PGF(2 alpha) during the process of luteolysis. In contrast, a developing corpus luteum (CL) is refractory to exogenous administration of PGF(2 alpha). Thus, the present study was aimed to investigate the functional relationship between ET-1 and PGF(2 alpha) in the mid-CL (PGF(2 alpha)-sensitive) and early-CL (PGF(2 alpha)-refractory). In the mid-CL model, cows (n = 6/treatment) were assigned to receive one of five types of treatments on day 10 of the estrous cycle: (1) an injection of saline; control, (2) a 500 jig of PGF2. analogue (sufficient dose to induce luteolytis); full-PG, (3) an intraluteal injection of 0.25 mg ET-1; ET-1, (4)... |
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Palavras-chave: Endothelin-1; Prostaglandin F-2 alpha; Luteolysis; Corpus luteum; Cow. |
| Ano: 2006 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/825 |
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| 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... |
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Palavras-chave: Blood vessels; Corpus luteum; ENOS; Luteolysis. |
| Ano: 2010 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2989 |
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| 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... |
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Palavras-chave: Cadherin; Connexin; Corpus luteum; Cow; Luteolysis. |
| Ano: 2007 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2988 |
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| 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... |
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Palavras-chave: Corpus luteum; Cow; Luteolysis; Prostaglandin F2α. |
| Ano: 2010 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2812 |
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| 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 >18, n=19). The... |
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Palavras-chave: Angiopoietin; Angiolysis; Luteolysis; Corpus luteum; Cow. |
| Ano: 2004 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2977 |
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