J Korean Androl Soc.  1995 Jan;13(1):7-12.

Cavernosal Response to Nonadrenergic-Noncholinergic Stimulation Compared with Response to Exogenous Nitric Oxide

• Jung GW
• Yoon JH

Abstract

Nitric oxide (NO) has been known to be endothelium-derived relaxing factor (EDRF) and the nonadrenergic-noncholinergic (NANC) neurotransmitter involved in the relaxation of cavernous smooth muscle. This study was initiated to characterize NANC neurotransmission after electrical field stimulation (EFS) in compared with exogenous NO administration. Using an organ bath, isometric tension measurements were made in strips of rabit corpus cavernous smooth muscle. The relaxation response elicited by exogenous NO was very similar to that evoked by EFS via the NANC pathway. The relaxant responses to NANC neurotransmission after EFS were almost abolished by NO synthase inhibitor NG-nitro-L-arginine (L-NOARG) (100 muM) (p<0.001), and were significantly inhibited by oxyhemoglobin (100 muM) which has a high binding affinity for NO in the extracellular compartment (p<0.025). Relaxation of corpus cavernosum in response to exogenous NO was almost abolished by oxyhemoglobin (100 muM) (p<0.001) but was not influenced by L-NOARG (100 muM). Our findings suggest that NO is a potent relaxant of rabbit cavernous smooth muscle via NANC neurotransmission by EFS. Endogenous No is the principal mediator of penile erection caused by NANC stimulation.

MeSH Terms

Baths
Endothelium
Endothelium-Dependent Relaxing Factors
Male
Muscle, Smooth
Neurotransmitter Agents
Nitric Oxide Synthase
Nitric Oxide*
Nitroarginine
Oxyhemoglobins
Penile Erection
Relaxation
Synaptic Transmission
Endothelium-Dependent Relaxing Factors
Neurotransmitter Agents
Nitric Oxide
Nitric Oxide Synthase
Nitroarginine
Oxyhemoglobins