Uckert Stefan, Becker Armin J, Ness Björn O, Stief Christian G, Scheller Friedemann, Knapp Wolfram H, Jonas Udo
Department of Urology, Hannover Medical School, Carl-Neuberg Str. 1, 30625 Hannover, Germany.
World J Urol. 2003 May;20(6):323-6. doi: 10.1007/s00345-002-0300-5. Epub 2002 Oct 17.
It is well established that transmitters of the nonadrenergic-noncholinergic (NANC) system are involved in the control of sexual arousal and penile erection in healthy males. The proerectile activity of dopamine D1/D2 receptor agonist apomorphine-HCl (IXENSE, UPRIMA) involves oxytocinergic pathways descending from the hypothalamus to the brain stem and spinal autonomic centers. Although it has been demonstrated that injection of oxytocin into the paraventricular nucleus and the hippocampus produces penile erection in rats, the significance of the peptide in the control of sexual arousal and penile erection in man has been, up until now, only poorly evaluated. The present study was undertaken to determine whether oxytocin (OT) plasma levels alter in the systemic and cavernous blood of healthy males under different penile conditions (flaccidity, tumescence, rigidity, detumescence). Twenty-five healthy adult males were exposed to visual and tactile erotic stimuli in order to elicit penile tumescence and rigid erection. Blood was taken from the corpus cavernosum (CC) and the cubital vein (CV) during penile flaccidity, tumescence, rigidity and detumescence. Following extraction from plasma aliqouts, oxytocin was measured by means of a radioimmunoassay. An increase was observed in the mean OT plasma levels in the systemic and cavernous blood when the flaccid penis became tumescent (CC: from 66.7+/-34 to 75+/-44 pg/ml; CV: from 71+/-41 to 79+/-49.5 pg/ml). From tumescence to rigidity, OT further rose in the cavernous blood (to 81+/-58 pg/ml), whereas it remained unaltered in the systemic circulation. During detumescence, oxytocin plasma levels dropped in the cavernous but again increased in the systemic blood (to 94+/-49 pg/ml). Our results support the hypothesis of a pivotal role of OT in the mechanism of male sexual arousal and penile erection and provide a rationale for the use of apomorphine in the treatment of erectile dysfunction.
众所周知，非肾上腺素能-非胆碱能（NANC）系统的递质参与健康男性性唤起和阴茎勃起的调控。多巴胺D1/D2受体激动剂盐酸阿扑吗啡（IXENSE，UPRIMA）的促勃起活性涉及从下丘脑下行至脑干和脊髓自主神经中枢的催产素能通路。尽管已证实向大鼠室旁核和海马注射催产素可使其阴茎勃起，但迄今为止，该肽在人类性唤起和阴茎勃起调控中的意义评估甚少。本研究旨在确定在不同阴茎状态（疲软、肿胀、坚硬、消退）下，健康男性全身血液和海绵体血液中催产素（OT）的血浆水平是否会发生变化。25名健康成年男性接受视觉和触觉性刺激以引发阴茎肿胀和坚硬勃起。在阴茎疲软、肿胀、坚硬和消退期间，从海绵体（CC）和肘静脉（CV）采集血液。从血浆样本中提取后，通过放射免疫分析法测定催产素。当疲软阴茎肿胀时，观察到全身血液和海绵体血液中OT的平均血浆水平升高（CC：从66.7±34至75±44 pg/ml；CV：从71±41至79±49.5 pg/ml）。从肿胀到坚硬，海绵体血液中的OT进一步升高（至81±58 pg/ml），而全身循环中的OT保持不变。在消退过程中，海绵体中的催产素血浆水平下降，但全身血液中的OT再次升高（至94±49 pg/ml）。我们的结果支持OT在男性性唤起和阴茎勃起机制中起关键作用的假说，并为阿扑吗啡用于治疗勃起功能障碍提供了理论依据。
