Chu Xi, Agmo Anders
Department of Medical Physiology, University of Tromsø, Tromsø, Norway.
Pharmacol Biochem Behav. 2008 Apr;89(2):209-17. doi: 10.1016/j.pbb.2007.12.012. Epub 2008 Jan 16.
Several proerectile drugs act on the nitric oxide-cyclic guanosine monophosphate pathway, which is known to influence rat copulatory behavior. In the present study we evaluated the effects of two proerectile compounds, one (Impaza) acting on endothelial nitric oxide synthase, and the other (sildenafil) on phosphodiesterase 5, on sexual incentive motivation in male rats displaying a spontaneously low level of motivation and copulatory behavior. About 20 months old male Fisher 344 rats were tested in a procedure for evaluating the intensity of sexual incentive motivation and in standard mating tests. For comparison, a group of young (about 4 months) Fisher 344 males was tested in parallel. This group did not receive any drug treatment. Impaza was administered in two doses, daily for 28 days, and sildenafil was given at a dose of 3 mg/kg twice a week during 28 days. Tests for sexual incentive motivation and copulatory behavior were performed immediately before the beginning of drug treatments, and on days 7, 14 and 28 of treatment. All treatment groups displayed a very low level of copulatory behavior and a sexually receptive female was not a more powerful incentive than another male at the tests performed before and on days 7 and 14 of treatment. On day 28 of treatment, the group treated with Impaza, 3 ml, displayed a preference for the sexually receptive female, while no such preference was found in the other groups. Furthermore, the preference score was above that of controls in this group. Both Impaza, 3 ml, and sildenafil reduced approach to the male in the test for sexual incentive motivation, suggesting that social motivation was reduced. These data suggest that compounds affecting the nitric oxide-cyclic guanosine monophosphate pathway may modify both sexual and social motivation in old rats.
几种助勃起药物作用于一氧化氮 - 环磷酸鸟苷途径，已知该途径会影响大鼠的交配行为。在本研究中，我们评估了两种助勃起化合物对性动机低下且交配行为自发减少的雄性大鼠的性动机的影响，其中一种（因帕扎）作用于内皮型一氧化氮合酶，另一种（西地那非）作用于磷酸二酯酶5。约20月龄的雄性费希尔344大鼠在一项评估性动机强度的实验程序以及标准交配试验中接受测试。作为对照，一组年轻（约4月龄）的费希尔344雄性大鼠同时进行平行测试。该组未接受任何药物治疗。因帕扎分两个剂量给药，每日一次，共28天，西地那非以3 mg/kg的剂量每周给药两次，持续28天。在药物治疗开始前以及治疗的第7、14和28天进行性动机和交配行为测试。在治疗前以及治疗第7天和第14天进行的测试中，所有治疗组的交配行为水平都非常低，且性接受期的雌性大鼠并不比另一只雄性大鼠更具吸引力。在治疗的第28天，接受3 ml因帕扎治疗的组表现出对性接受期雌性大鼠的偏好，而其他组未发现这种偏好。此外，该组的偏好得分高于对照组。3 ml因帕扎和西地那非在性动机测试中均均降低雄性接近行为测试中均降低，这表明社交动机降低。这些数据表明，影响一氧化氮 - 环磷酸鸟苷途径的化合物可能会改变老年大鼠的性动机和社交动机。
