Role of the Dopaminergic, Serotonergic and Cholinergic Link in the Expression of Penile Erection in Rats

The Japanese Journal of Pharmacology

Isamu Yamaguchi¹  Nobuya Matsuoka¹  Noriaki Maeda¹ 

[1] Basic Research Group, Tsukuba Research Laboratories, Fujisawa Pharmaceutical Co., Ltd.

关键词: Penile erection;    Cholinergic;    Serotonergic;    Dopaminergic;    Septo-hippocampal pathway;   

DOI  :  10.1254/jjp.66.59

学科分类：药理学

来源: Nihon Yakuri Gakkai Henshuubu / Japanese Pharmacological Society

【 摘 要 】

References(35)Cited-By(6)The neural mechanisms underlying the penile erection induced by serotonergic, cholinergic and dopaminergic stimulants were comparatively investigated. Fenfluramine (0.1-10 mg/kg, i.p.), pilocarpine (0.032-3.2 mg/kg) and apomorphine (0.01-1 mg/kg) induced penile erection in rats with bellshaped dose-response curves. The penile erection induced by fenfluramine (1 mg/kg) was dose-dependently antagonized by pindolol (0.1-3.2 mg/kg), a 5-HT1 antagonist, or scopolamine (0.032-1 mg/kg), a muscarinic antagonist, but not by sulpiride (1-32 mg/kg), a dopaminergic antagonist. The penile erection induced by pilocarpine (0.32 mg/kg) was countered by pindolol or scopolamine but not by sulpiride, while that induced by apomorphine (0.032 mg/kg) was countered by all three antagonists. Septo-hippocampal cholinergic deafferentations by medial septum lesioning or fimbria-fornix transection also significantly attenuated the penile erection induced by fenfluramine or apomorphine, but scarcely affected that induced by pilocarpine. Raphe lesion by injections of 5, 7-dihydroxytryptamine, a serotonergic neurotoxin, into the median and dorsal-raphe nuclei significantly attenuated the penile erections induced by fenfluramine and apomorphine but not that by pilocarpine. These results suggest that a neuronal link between the dopaminergic, serotonergic and cholinergic systems plays a crucial role in the expression of penile erection; dopaminergic stimulation causes an activation of the raphe serotonergic neurons which in turn enhances the septo-hippocampal cholinergic pathway and results in expression of penile erection.

【 授权许可】

Unknown