Prostaglandin F2 alpha promotes the inhibitory action of endothelin-1 on the bovine luteal function in vitro.
Prostaglandin F2 alpha promotes the inhibitory action of endothelin-1 on the bovine luteal function in vitro.
复制标题
体外前列腺素 F2 α 促进内皮素 1 对牛黄体功能的抑制作用。
作者：
Akio Miyamoto;S. Kobayashi;S. Arata;M. Ohtani;Y. Fukui;D. Schams
前列腺素F2α(PGF2α)是奶牛体内的一种主要的黄体素。虽然黄体溶解的机制被认为是其对黄体细胞的直接作用和对黄体血流的间接作用的综合作用，但其具体机制仍有待阐明。本研究旨在探讨内皮细胞来源的内皮素-1(ET-1)与前列腺素F2α(PGF2α)在快速抑制黄体(CL)孕酮释放过程中的可能相互作用。在CL的体外微透析系统(MDS)中，PGF2α可显著刺激输注中孕酮和催产素的释放以及输注后ET-1的释放。此外，在实验的最后阶段(PGF2α暴露后8~11h)，PGF2α诱导的孕酮释放略有下降。间隔3h的两次1h的ET-1灌流仅引起第二次灌流后孕酮释放的轻微下降。这种治疗也影响催产素的释放；第一次ET-1灌流产生急性刺激，而第二次ET-1灌流将催产素释放抑制到50%以下。用PGF2α预灌流CL段2 h后，间隔3h连续两次灌流ET-1，仅在第二次灌流ET-1后，孕酮和催产素的释放才显著降低。因此，预先接触PGF2α明显增强了ET-1对孕酮释放的抑制活性。这些结果提示，PGF2α和ET-1在体内功能性黄体溶解的快速级联过程中起生理学作用，内皮细胞和黄体细胞之间可能存在相互作用。
Prostaglandin F2 alpha (PGF2 alpha) is a primary luteolysin in the cow. Although the mechanisms involved in luteolysis are thought to be a complex of its direct action on luteal cells and indirect effect on luteal blood flow, the detailed mechanisms remain to be elucidated. This study focuses on the possible interaction of endothelial cells-derived endothelin-1 (ET-1) with PGF2 alpha in the rapid suppression of progesterone release from the bovine corpus luteum (CL). In in vitro microdialysis system (MDS) of CL, PGF2 alpha acutely stimulated the release of progesterone and oxytocin during infusion and ET-1 release after infusion. Moreover, PGF2 alpha induced slight decrease of progesterone release during the last period of the experiment (8-11 h after PGF2 alpha exposure). Two 1 h-perfusions of ET-1 at 3 h intervals induced only a slight decrease of progesterone release after the second perfusion. This treatment also affected the oxytocin release; the first ET-1 perfusion produced an acute stimulation, whereas the second ET-1 perfusion inhibited the release to below 50%. When the CL pieces were pre-perfused with PGF2 alpha for 2 h, the two consecutive perfusion of ET-1 at 3 h intervals induced drastic decrease in progesterone and oxytocin release only after the second ET-1 perfusion. Thus, a pre-exposure with PGF2 alpha clearly potentiated the inhibiting activity of ET-1 in the progesterone release. These results suggest a physiological impact of PGF2 alpha and ET-1 in the rapid cascade of functional luteolysis in vivo, and a possible interaction between endothelial cells and luteal cells.