Holmes G M, Bresnahan J C, Beattie M S
Department of Neuroscience, The Ohio State University, 4068 Graves Hall, 333 West Tenth Avenue, Columbus, OH 43210-1239, USA.
Physiol Behav. 2001;74(1-2):57-64. doi: 10.1016/s0031-9384(01)00512-1.
The effects of serotonin (5-HT) and thyrotropin-releasing hormone (TRH) on penile reflexes were investigated in intact and spinally transected male rats. Doses of intrathecal 5-HT (0.0, 1.13, 2.26, 11.3, 22.6, and 113.0 nmol), in a range previously shown to inhibit pudendal reflexes in anesthetized spinal preparations, prolonged the latency to the first penile erection in awake intact rats. However, these doses also provoked hyperreactivity and vocalization. Doses of intrathecal TRH (100 and 500 pmol) that effectively inhibited penile erection in intact animals were less effective in spinalized animals. Finally, a combination of subthreshold doses of TRH (100 pmol) and 5-HT (4.0 nmol) at a ratio known to affect other TRH/5-HT-mediated circuits significantly extended erection latency in animals with spinal transections. These data suggest that 5-HT and TRH are both involved in the inhibitory circuits regulating penile erection, either through corelease onto the same population of cells or through independent release onto different populations of neurons.
在完整和脊髓横断的雄性大鼠中研究了血清素（5-羟色胺，5-HT）和促甲状腺激素释放激素（TRH）对阴茎反射的影响。鞘内注射5-HT的剂量（0.0、1.13、2.26、11.3、22.6和113.0纳摩尔），在先前已证明可抑制麻醉脊髓制剂中阴部反射的范围内，延长了清醒完整大鼠首次阴茎勃起的潜伏期。然而，这些剂量也引发了反应过度和发声。在完整动物中有效抑制阴茎勃起的鞘内注射TRH剂量（100和500皮摩尔），在脊髓横断动物中效果较差。最后，已知影响其他TRH/5-HT介导回路的比例的阈下剂量的TRH（100皮摩尔）和5-HT（4.0纳摩尔）组合，显著延长了脊髓横断动物的勃起潜伏期。这些数据表明，5-HT和TRH都参与调节阴茎勃起的抑制性回路，要么通过共同释放到同一群细胞上，要么通过独立释放到不同群神经元上。
