Forskolin does not augment the bradykinin response of canine visceral polymodal receptors in vitro

Abstract

In clarifying the possible involvement of cyclic AMP (cAMP) in prostaglandin (PG) E2-induced sensitization of the bradykinin response of canine testicular polymodal receptors, the effects of forskolin, an activator of adenylyl cyclase, were studied in the presence and absence of acetylsalicylic acid (ASA, 550 microM) which blocks PG production. Forskolin (10 microM) seldom induced discharges in polymodal receptors. An unexpected outcome of this study was that forskolin induced no facilitation of the bradykinin (0.1 microM) response, both in the absence and presence of ASA. A slight yet significant suppression of the bradykinin response was instead observed in the absence of ASA. These results suggest that intracellular cAMP may be related with PG E2-induced sensitization of the bradykinin response through its decrease.