Involvement of brain serotonin in regulation of sexual maturity in male rats.

We have studied the effect of a reduction in the serotonin level at different times in the prepubertal period on the neuroendocrine and morphometric characteristics of sexual maturation of male rats. We established that injection of p-chlorophenylalanine, a blocker of serotonin synthesis, into male rats on the 30th and 34th day of life leads to activation of the endocrine function of the testes in 60-day-old animals. Injection of the preparation at later times, 40th and 44th day, produced a marked inhibiting effect on sexual maturation, expressed as inhibition of both the spermatogenic and the endocrine function of the testes of the animals investigated. The data obtained allow an assessment of the dual role of serotonin in the regulation of the rate of sexual maturation of male rats at different prepubertal periods.