Project/Area Number |
19580326
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Applied animal science
|
Research Institution | Okayama University |
Principal Investigator |
ACOSTA T・j Okayama University, 大学院・自然科学研究科, 准教授 (80379718)
|
Co-Investigator(Kenkyū-buntansha) |
奥田 潔 岡山大学, 大学院・自然科学研究科, 教授 (40177168)
|
Project Period (FY) |
2007 – 2009
|
Project Status |
Completed (Fiscal Year 2009)
|
Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2009: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2008: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2007: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
|
Keywords | ウシ / 一酸化窒素 / 発情周期 / 内分泌 / 黄体 / 子宮 / プロスタグランジンF2α / 酸素 / 黄体退行 / 黄体血管内皮細胞 / 活性酸素 / 繁殖 / サイトカイン |
Research Abstract |
Clarification of the mechanism controlling the regression of corpus luteum by reactive oxygen species The corpus luteum (CL) is a transient endocrine gland, which is essential for the regulation of ovarian cycles as well as for establishment and maintenance of pregnancy. The luteal regression is characterized by a loss of the capacity to produce progesterone (P_4) functional luteolysis and tissue degeneration structural luteolysis. Prostaglandin F_<2α> (PGF) and reactive oxygen species (ROS) are implicated in the functional and structural luteolysis. To determine the physiological role of PGF and ROS in the local regulation of CL function in cows, I examined 1) the effect of PGF on nitric oxide (NO) generating system in bovine luteal endothelial cells (LECs) and 2) the roles of PGF and ROS in the regulation of superoxide dismutase (SOD) enzyme in bovine LECs. 1) PGF receptor (FPr) mRNA and protein were expressed in cultured LECs obtained from mid-stage CLs. PGF increased NO (nitrite and
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nitrate) concentra- tions in the medium of cultured LECs. When LECs were exposed to 1μM PGF, PGF did not affect the expressions of endothelial NO synthase (eNOS) mRNA and protein. On the other hand, PGF stimulated the expression of inducible NOS (iNOS) mRNA and protein. In addition, PGF stimulated the NOS activity in cultured LECs (P<0.05). 2) When LECs were exposed to PGF, H_2O_2 or NONOate (NO donor) for 2 or 24 h. PGF, H_2O_2 and NONOate stimulated SOD mRNA and protein expression, and SOD activity at 2 h (P<0.05). On the other hand, PGF, H_2O_2 and NONOate inhibited SOD mRNA and protein expressions at 24 h (P<0.05). In addition, exposure of LECs to H_2O_2, NONOate and SOD induced an increase in PGF biosynthesis (2 h). The present results indicate that bovine LECs are target for PGF, and suggest that stimulation of the NO generating system and NOS activity induced by PGF result in increasing local NO production followed by luteolysis. The overall findings suggest the presence of a positive feedback loop between PGF and ROS in bovine LECs. SOD may play important roles in controlling the intraluteal ROS concentrations during functional and structural luteolysis in cows. Less
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