The Meaning of the Initial Drop in Canine Intracorporal Pressure During Erection

Paick, Jae Seung; Lee, An Kie; Kim, Myung Suk

Abstract

Most investigators now agree that active relaxation of smooth muscles of both the cavernous sinusoids and arterial tree take place concomitantly under neural control during erection. Recently we isolated and stimulated the cavernous nerves in 12 dogs. In 7 dogs which erection could be induced we measured the intracorporal pressure change during erection. In 2 dogs we observed initial drop in the intracorporal pressure for 14 to 20 seconds followed by a rise above prestimulation line, that had not been reported by other investigators. To evaluate the meaning of the initial drop in intracorporal pressure we review our clinical investigation and the state of knowledge of local hemodynamics of erection. Now we propose a new theory about the mechanism that control penile arterial smooth muscle. The relaxation of penile arterial smooth muscle seems to be a secondary reactive response for adjusting to blood requirement after relaxation of the smooth muscle of the cavernous smooth muscle. Secondary reactive response means non neurogenic autoregulation. We propose myogenic theory or non neurogenic, flow induced, endothelium-dependent relaxation as the mechanism of autoregulation for penile arterial flow.