去卵巢大鼠Ru 486与垂体及子宫内膜孕激素受体结合的比较

THE COMPARISON OF THE BINDING OF Ru486 TO PROGESTERONE RECEPTOR OF PITUITARY AND ENDOMCETRIUM IN OVARIECTOMIZED RAT

经雌激素诱发的去卵巢大鼠在肌肉注射不同量的 Ru486(0.1mg/kg—2mg/kg)之后,垂体及子宫内膜的胞液游离孕激素受体结合位点随着 Ru486注射量的升高而逐步下降。注射 Ru486 2mg/kg 30min 后,此两组织中孕激素受体的结合位点就明显降低,2h 降到最低点,3h 开始恢复。以上实验说明 Ru486进入机体即可分别占领垂体及子宫内膜的孕激素受体的结合位点。然而 Ru486对此二组织的孕激素受体的结合作用并不完全相同,似乎子宫孕激素受体更易为 Ru486所占位,而解离也快。

Following intramuscular injections of increasing doses of Ru486(0.1 mg/kg—2 mg/kg),free progesterone binding sites remaining in pituitary and endometri-um in estrogen-primed OVX rats decreased.Thirty minutes after administrationof Ru486(2 mg/kg)the binding sites of progesterone receptor in both tissues showeda significant initial decrease,and then gradually reached the lowest level in 2 h.Afterwards the levels of progesterone receptor began to increase.The resultssuggested that Ru486 could interact with progesterone receptor in both tissues.However,the binding ability of Ru486 for different tissue was not exactly thesame,and Ru486 binding to the progesterone receptor in endometrium mightbe easier.