Progesterone increases cAMP release and accumulation in isolated term human myometrium.

OBJECTIVE

To study the relationship between the action of progesterone on term human myometrial contractile activity and cAMP alterations.

STUDY DESIGN

Myometrial tissues were obtained from 13 term pregnant women who underwent elective cesarean section. The contractile activity of muscle strips was recorded isometrically, and the level of cAMP in both superfusion media and experimental biopsies was measured by radioimmunoassay.

RESULTS

An increased cAMP release into the superfusion media and an increased accumulation of cAMP in myometrium were observed after the addition of progesterone (3, 15 and 150 microM). Simultaneously, the frequency and tonus of contractions were increased, while the amplitude and activity area of contractions were decreased.

CONCLUSIONS

The data indicate that an increase in cAMP concentration plays a role in the action of progesterone on the regulation of term human myometrial contractile activity.