J Korean Androl Soc.  1993 Dec;11(2):63-67.

Relaxation of internal pudendal artery by acetylcholine is involved in penile erection

• Suh MY
• Suh JK
• Shin HC
• Kim YS
• Park TC
• Byun WM
• Cho KH

Abstract

Recent in vitro studies have demonstrated that acetylcholine(ACh) relaxes cavernosal smooth muscle by causing the release of endothelium-derived relaxing factor(EDRF). However, it is not clear how the penile arterial system is involved in erection or how autonomic nervous control affects the relaxation or contraction of that arterial system. The present study was designed to investigate the in vivo pharmacologic response of the internal pudendal artery(!PA) to intraarterial injection of ACh. Pudendal angiography was performed in 14 patients with venogenic impotence before and injection of ACh(50 microgram or 100 microgram ) through the hypogastric artery. The ACh was found to increase the luminal diameter of the IPA in a dose-dependent manner. The dilating effect was more prominent in the distal portion(23.5;8.6%) than the proximal portion(15.1;6.0%) of the artery. These results, together with the previous in vitro data, indicate that ACh-induced relaxation of the IPA-penile arterial system is mediated by EDRF and that the more distal branch of this arterial system may be actively involved in penile erection.

MeSH Terms

Acetylcholine*
Angiography
Arteries*
Erectile Dysfunction
Female
Humans
Impotence, Vasculogenic
Injections, Intra-Arterial
Male
Muscle, Smooth
Penile Erection*
Phenobarbital
Relaxation*
Acetylcholine
Phenobarbital