[D丙~6,脯~9乙基胺]-促黄体素释放激素LH-RHA对妊娠兔子宫内膜多聚核糖体mRNA的作用

本实验制备了非孕兔、孕兔和绐孕兔注射高剂量[D丙‘,脯’乙基胺]-促黄体素释放激素(LH-RH A)不同天数的子宫内膜多聚核糖体,并从多聚核糖体提取mRNA,在网织红细胞无细胞翻译系统中测定了活性。结果指出用LH-RH A处理后多聚核糖体mRNA量减少,其翻译活性降低,在体内实验中核糖体mRNA诱导兔子宫分秘蛋白的合成也受到抑制,特别是分子量大约为22,000和69,000左右的分泌蛋白合成受到明显抑制。

THE ACTION OF A LUTEINIZING HORMONE -RELEASING HORMONE ANALOGUE (LH-RH A) ON THE ENDOMETRIAL POLYSOMAL mRNA OF PREGNANT RABBITS

Cao et al. (1984) reported the presence of specific LH-RH receptors in the rat endometrium and a direct inhibitory effect of LH-RH A [(D-Ala6, Pro9-ethylamide)-LH-RH] on endometrial protein in pregnant rabbits in vivo; while Liu et al. (1984) investigated the direct effect of LH-RH A on the protein and nucleic acid metabolism in pregnant rat uterus in vitro. The present paper was designed to investigate the action of LH-RH A on the endometrial polysomal mRNA in pregnant rabbits.The results show the amount of endometrial polysomal mRNA in pregnant rabbits by treatment with 300 mg/kg/day LH-RH A is lower than that in the pregnant animals. Furthermore, its translation activity in reticulolysate system reduced as well. In vivo, the pregnant rabbit endometrial polysomal mRNA induced 2 significant uterine proteins with MW. about 22,000 and 69,000 by polyacrylamide gel electrophoresis. These 2 proteins almost disappeared in uterine proteins while introducing the pregnant rabbit endometrial polysomal mRNA treatment with LH-RH A. The results presented in this study provide further evidence to show that LH-RH A is directly involved in the regulation of the uterine protein synthesis by inhibition of the polysomal mRNA.