著者

永尾 光一

出版者

日本平滑筋学会

雑誌

Journal of smooth muscle research. Japanese section (ISSN:13428152)

巻号頁・発行日

vol.9, no.2, pp."J-37"-"J-45", 2005-08-01

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The mechanisms required for erection include nerve system, blood vascular system and endocrine system. Among them, the first two systems are especially important. The pelvic nerve accelerates erection. The hypogastric nerve suppresses erection and relates to ejaculation. Further, the NANC (non-adrenergic non-cholinergic) nervous system included in the cavernous nerve plays a key role in stimulating erection. Nitrogen monoxide (NO) is synthesized at the nerve ending. NO infiltrates the cavernous artery, spiral artery and smooth muscle and stimulates guanylate cyclase to produce cGMP from GTP. This cGMP combines to cGMP specific protein kinase to reduce the intracellular calcium concentration. Then, the cavernous artery, spiral artery and the smooth muscle of the trabeculae of corpus spongiosum are relaxed. The arterial blood flows into the sponge-like cavernous sinus to stimulate erection.