Department of Psychology, University of Tromsø, Tromsø, Norway.
Pharmacol Biochem Behav. 2012 Dec;103(2):345-52. doi: 10.1016/j.pbb.2012.09.007. Epub 2012 Sep 12.
Premature ejaculation is the most common sexual disorder in young men. Consequently, there is an intense search for efficient and safe pharmacological treatments. Insofar, almost no effective treatment with acute effects is available. In this study, we evaluated the effects of the noradrenergic α(2) receptor agonist dexmedetomidine on sexual incentive motivation and copulatory behavior in male rats. Sexual incentive motivation was tested in a large rectangular arena connected to two small incentive stimulus cages containing either a male or sexually receptive female rat. There was no sexual interaction possible between the experimental subjects and the incentives during this test. Approach to the incentives constituted the measure of sexual incentive motivation. After the sexual incentive motivation test, the subjects were tested for copulatory behavior in a regular copulation test for 30min. Doses of 0.1 and 1μg/kg of dexmedetomidine (i.p.) had no effect on any of the indices of locomotor activity or on parameters of sexual incentive motivation. With regard to copulatory behavior, it was found that the dose of 1μg/kg prolonged the latency to the first ejaculation, while the latency to second ejaculation showed a tendency to increase. The absence of an effect on indices of sexual incentive motivation or general activity showed that the actions of dexmedetomidine in this study were limited to ejaculatory mechanisms. Insofar as the ejaculation latency in the male rat is predictive of prolonged ejaculation latency in men, it can be proposed that dexmedetomidine is of potential utility for the treatment of premature ejaculation.
早泄是年轻男性最常见的性障碍。因此，人们强烈寻求有效且安全的药物治疗方法。迄今为止，尚无有效的急性治疗方法。在这项研究中，我们评估了去甲肾上腺素能 α(2)受体激动剂右美托咪定对雄性大鼠性激励动机和交配行为的影响。在一个与两个小激励刺激箱相连的大型矩形竞技场中测试性激励动机，这些小激励刺激箱中包含雄性或接受过性刺激的雌性大鼠。在这个测试中，实验对象与激励因素之间不可能进行任何性互动。接近激励因素构成了性激励动机的衡量标准。在性激励动机测试之后，对动物进行了 30 分钟的常规交配测试，以测试它们的交配行为。0.1 和 1μg/kg 的右美托咪定（ip）剂量对运动活动的任何指标或性激励动机的参数均没有影响。关于交配行为，发现 1μg/kg 的剂量延长了首次射精的潜伏期，而第二次射精的潜伏期有增加的趋势。由于右美托咪定对性激励动机或一般活动的指标没有影响，因此可以认为其在这项研究中的作用仅限于射精机制。由于雄性大鼠的射精潜伏期可预测男性射精潜伏期的延长，因此可以提出右美托咪定可能对治疗早泄有用。
