ADENYLYL-CYCLASE ACTIVITY IN HUMAN DECIDUA AND MYOMETRIUM DURING PREGNANCY AND LABOR

Adenylyl cyclase activity was studied in human decidua and myometrium in early pregnancy and at term before and after the onset of labour. D ecidual basal, prostaglandin-, catecholamine- and forskolin-stimulated adenylyl cyclase activities at term before the onset of labour were s ignificantly lower than those in early pregnancy. After the onset of l abour at term, decidual basal, prostaglandin-, catecholamine-, NaF- an d forskolin-stimulated adenylyl cyclase activities significantly incre ased compared with those at term before the onset of labour. Myometria l prostaglandin- and catecholamine-stimulated activities did not after during pregnancy, except for basal and forskolin-stimulated activity. Myometrial basal, prostaglandin-, catecholamine-, NaF- and forskolin- stimulated activities at term showed no change after the onset of labo ur. At term, before the onset of labour, myometrial basal, prostagland in, catecholamine-, NaF- and forskolin-stimulated activities were the same as those in the decidua. However, after the onset of labour at te rm, decidual basal and the stimulated activities were significantly hi gher than those in the myometrium. These results suggest that decidual prostaglandin- and catecholamine-stimulated adenylyl cyclase may play an important role in the initiation or maintenance of human labour or in both processes.