PARTIAL MEDIATION BY NITRIC-OXIDE OF THE RELAXATION OF HUMAN ISOLATED DETRUSOR STRIPS IN RESPONSE TO ELECTRICAL-FIELD STIMULATION

1 A method for reproducing relaxation of human isolated detrusor smooth muscle in vitro in response to electrical field stimulation is described. 2 The parameters of stimulation associated with relaxation were those which would be expected to give a largely nerve-mediated response: the relaxations were not reduced by tetrodotoxin (3 x 10(-7) M) and were therefore not dependent on voltage sensitive sodium channels. 3 The relaxations were decreased (mean 74. 1%) by nitro L-arginine (NOARG, 10(-5) M). 4 Methylene blue (10(-5) M), an inhibitor of soluble guanylate cyclase, abolished the relaxations. 5 These results indicate that there may be a relaxation mechanism in the human bladder which is at least partly mediated via the production of nitric oxide.