1. ¹Departamento de Agrobiología, Universidad Autónoma de Tlaxcala, Tlaxcala, Mexico
2. ²Laboratorio de Tlaxcala, Centro de Investigacion y Estudios Avanzados, Tlaxcala, Mexico
3. ³Departamento de Fisiologia, CINVESTAV del I.P.N., Tlaxcala, Mexico

Correspondence: R Cueva-Rolon, Centro de Investigacion y Estudios Avanzados, Laboratorio de Tlaxcala, Plaza Hidalgo s/n, Panotla, Tlaxcala 90140, Mexico. E-mail: laboratorio@servired.com.mx

Received 10 December 2002; Revised 1 August 2003; Accepted 22 September 2003.

Abstract

Penile reflexes (PRs) were monitored in chronic spinal cord-transected rats by identifying them visually, and at the same time they were recorded as the electromyographic activity of bulbospongiosus muscles. Intraperitoneal injection of the agonist muscarine (10 g) produced a facilitation of PRs. A decrease in the latency, an increase in the number of clusters and often an increase in the duration of cups were found after muscarine. In addition, 66% (six out of nine) of the animals ejaculated after muscarine. These results suggest that cholinergic receptor stimulation may be involved in erectile and ejaculatory mechanisms mediated by the spinal cord.