CHANGES IN ADENYLYL CYCLASE ACTIVITY IN HUMAN ENDOMETRIUM DURING THE MENSTRUAL-CYCLE AND IN HUMAN DECIDUA DURING PREGNANCY

Adenylyl cyclase activity was studied in human endometrium during the menstrual cycle and in human decidua during pregnancy. Higher adenylyl cyclase activity was found in the endometrium than in the myometrium, corpus luteum or Fallopian tubes. In the endometrium, the basal and s timulated activities were highest in the fundus and decreased slightly from the fundus to the isthmus. Prostaglandin-stimulated adenylyl cyc lase activity increased gradually from the proliferative phase to the secretory phase, and then quickly reached its highest value in the lat e secretory phase. Catecholamine-stimulated adenylyl cyclase activity reached a peak in the late proliferative phase and decreased significa ntly thereafter. Forskolin-stimulated activity was significantly highe r throughout the secretory phase than in the proliferative phase. In t he decidua, prostaglandin-, catecholamine- and forskolin-stimulated ad enylyl cyclase activities in late pregnancy were significantly lower t han those in early pregnancy. Our results demonstrate dramatic alterat ions in adenylyl cyclase activity in human endometrium during the mens trual cycle and in human decidua during pregnancy.