The effect of histamine on cyclic AMP levels in guinea-pig tracheal smooth muscle

Abstract

Histamine (10(-5)--3 x 10(-4) M) increased the cylic AMP content of guinea-pig tracheal smooth muscle, the maximal effect being a 3-fold increase after 2-min incubation with 10(-4) histamine. Histamine-induced accumulation of cyclic AMP was not affected by propranolol or atropine, but was reduced by mepyramine. Aspirin and indomethacin abolished the cyclic AMP response to histamine and potentiated histamine-induced contractions of the smooth muscle. These results suggest that the elevation of cyclic AMP levels in response to histamine is mediated by prostaglandins, and represents an important negative feedback regulatory mechanism which modulates the contractile response of guinea-pig tracheal smooth muscle to histamine.