title: Lack of effect of carbon monoxide inhibitor on relaxation induced by electrical field stimulation in corpus cavernosum.
abstract: Carbon monoxide has been proposed as a possible neurotransmitter because of its ability to bind to the iron atom of the heme of guanylyl cyclase, which is similar to that of nitric oxide. To determine whether carbon monoxide exerts an effect on the penis, strips of rabbit corpus cavernosum were mounted in an organ bath for isometric tension studies and the effect of zinc deuteroporphyrin, an inhibitor of heme oxygenase which metabolizes hemoprotein and releases carbon monoxide, on relaxation induced by electrical field stimulation (neurally mediated) was determined. Also observed was relaxation induced by electrical field stimulation after incubation with atropine and guanethidine to isolate nonadrenergic noncholinergic neurotransmission. Zinc deuteroporphyrin (10(-6) M, 10(-5) M, 10(-4) M and 3 x 10(-4) M) did not affect relaxation induced by electrical field stimulation in the absence or presence of guanethidine and atropine. Therefore, it appears that carbon monoxide does not contribute to neurally mediated relaxation of the rabbit corpus cavernosum.
authors.affiliation: Sexual Dysfunction Laboratory, University of North Carolina School of Medicine.
authors.forename: Y C
authors.initials: YC
authors.lastname: Kim
authors.forename: M G
authors.initials: MG
authors.lastname: Davies
authors.forename: L
authors.initials: L
authors.lastname: Marson
authors.forename: P O
authors.initials: PO
authors.lastname: Hagen
authors.forename: C C
authors.initials: CC
authors.lastname: Carson
mesh_terms: D000818:Animals; D002248:Carbon Monoxide / Q000037:antagonists & inhibitors*; D003905:Deuteroporphyrins / Q000494:pharmacology; D004558:Electric Stimulation; D006419:Heme Oxygenase (Decyclizing) / Q000037:antagonists & inhibitors; D066298:In Vitro Techniques; D008297:Male; D009126:Muscle Relaxation / Q000502:physiology*; D009130:Muscle, Smooth / Q000502:physiology*; D009569:Nitric Oxide / Q000037:antagonists & inhibitors; D010413:Penis / Q000502:physiology*; D011817:Rabbits; D015032:Zinc / Q000494:pharmacology
chemical_list: D003905:Deuteroporphyrins; D009569:Nitric Oxide; C028839:deuteroporphyrin-IX; D002248:Carbon Monoxide; D006419:Heme Oxygenase (Decyclizing); D015032:Zinc