Release of nitric oxide by nerve stimulation in the human urogenital tract.
Nerve-induced release of the nitric oxide (NO) breakdown products nitrite (NO2-) and nitrate (NO3-) and the histochemical localization of NO synthase in the human penile corpus cavernosum and urethra were studied. Relaxations induced by nerve stimulation were inhibited by N omega-nitro-L-arginine methyl ester (L-NAME), an effect which was reversed by L-arginine. Relaxations elicited either by nerve stimulation or exogenous NO were accompanied by the appearance of equivalent amounts of NO2- and NO3- over a very similar time course. Nerve-induced release of NO2- and NO3- was inhibited by L-NAME. Histochemical studies showed NADPH diaphorase and NO-positive nerve fibres surrounding the arteries and smooth muscle bundles in the corpus cavernosum and the urethra. The results suggest that NO is a mediator for non-adrenergic non-cholinergic relaxation in the human urogenital tract.
Leone
A M
AM
Wellcome Research Laboratories, Beckenham, Kent, UK.
Wiklund
N P
NP
Hökfelt
T
T
Brundin
L
L
Moncada
S
S
D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D004558:Electric Stimulation; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008297:Male; D009126:Muscle Relaxation / Q000502:physiology; D009252:NADPH Dehydrogenase / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019001:Nitric Oxide Synthase; D010413:Penis / Q000033:anatomy & histology / Q000378:metabolism* / Q000502:physiology; D014521:Urethra / Q000033:anatomy & histology / Q000378:metabolism* / Q000502:physiology
D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D009252:NADPH Dehydrogenase; D019331:NG-Nitroarginine Methyl Ester