Cell-cell communication mechanism in the corpus luteum

在本研究中，膜联蛋白V在黄体中的表达进行了调查的基础上的假设，膜联蛋白V将参与细胞间通讯的黄体。通过免疫细胞化学、原位杂交和北方印迹分析检测膜联蛋白5的表达，并特别参考黄体的功能阶段。膜联蛋白5是膜联蛋白家族蛋白质的一员，已被证明分布在卵巢中的黄体中。由于颗粒细胞不表达膜联蛋白5，推测卵巢组织中膜联蛋白5合成的调节机制未知。尽管免疫细胞化学分析显示annexin 5分布于大多数黄体细胞，但原位杂交显示只有大的黄体细胞表达annexin 5 mRNA，annexin 5 mRNA的表达在假孕中期显著下降，这种变化是由于黄体表达减少所致。比较妊娠12 d和假孕12 d卵巢组织中Annexin 5的表达，妊娠卵巢Annexin 5 mRNA表达较低，妊娠黄体中Annexin 5的膜结合明显，而假孕退化黄体中Annexin 5的膜结合很弱。在假孕中期给予溴麦角隐肽增加卵巢膜联蛋白5 mRNA。另一方面，从发情期开始每天两次给予周期大鼠催乳素，可显著降低间情期的水平。本研究结果表明，膜联蛋白5的大黄体细胞的黄体，这是负调控的功能性黄体期期间，由催乳素的优先表达。总的来说，这些数据表明膜联蛋白5在调节黄体功能的重要作用，通过细胞间通讯的黄体。

In the present study, the expression of annexin V in the corpus luteum was investigated on the basis of the hypothesis that annexin V would be involved in cell-cell communication in the corpus luteum. The expression of annexin 5 was examined by immunocytochemistry, in situ hybridization, and Northern blot analysis with special reference to the functional stage of corpus luteum. Annexin 5, a member of annexin family protein, has been shown to be distributed p referentially to the corpus luteum in the ovary. As granulosa cells do not express annexin 5, an unknown regulatory mechanism of annexin 5 synthesis in the ovarian tissue is presumed. Although immunocytochemical analysis of annexin 5 demonstrated the distribution of annexin 5 to most luteal cells, in situ hybridization showed that only large luteal cells express annexin 5 mRNA.The expression of annexin 5 mRNA was decreased significantly at mid-pseudopregnancy and this change was shown to be due to a decrease in luteal expression. When the expression of annexin 5 was compared in the ovarian tissue on the 12th day of both pregnancy and pseudopregnancy, the pregnant ovaries showed a lower expression of annexin 5 mRNA.While the membrane association of annexin 5 was distinctly observed in the pregnant corpus luteum, it was very slight in the regressing luteal cells of pseudopregnancy. Administration of bromoergocriptin at mid-pseudopregnancy increased annexin 5 mRNA of the ovary. On the other hand, administering prolactin to cycling rats twice daily from estrus significantly decreased the level at diestrus. The present results demonstrate the preferential expression of annexin 5 in the large luteal cells of the corpus luteum and that this is negatively regulated during the functional luteal phase by prolactin. Collectively, these data suggest a significant role of annexin 5 in the regulation of luteal function by means of cell-cell communication in the corpus luteum.