Effects of forskolin on contractility and cyclic AMP levels in rabbit detrusor muscle.

Forskolin caused a concentration-dependent relaxation and increase in cyclic AMP levels in rabbit detrusor muscle. Propranolol, a beta-adrenoceptor antagonist, did not affect the relaxation induced by forskolin. 3-isobutyl-1-metylxanthine (IBMX), a cyclic nucleotide phosphodiesterase inhibitor, potentiated the relaxation induced by forskolin. These data suggest that the relaxation of rabbit detrusor muscle induced by forskolin is mediated by cyclic AMP accumulation resulting from activation of adenylate cyclase.