Yc. Kim et al., LACK OF EFFECT OF CARBON-MONOXIDE INHIBITOR ON RELAXATION INDUCED BY ELECTRICAL-FIELD STIMULATION IN CORPUS CAVERNOSUM, Urological research, 22(5), 1994, pp. 291-293
Carbon monoxide has been proposed as a possible neurotransmitter becau
se of its ability to bind to the iron atom of the heme of guanylyl cyc
lase, which is similar to that of nitric oxide. To determine whether c
arbon 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 oxygena
se which metabolizes hemoprotein and releases carbon monoxide, on rela
xation 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 relaxa
tion induced by electrical field stimulation in the absence or presenc
e of guanethidine and atropine. Therefore, it appears that carbon mono
xide does not contribute to neurally mediated relaxation of the rabbit
corpus cavernosum