[Relationship between regulatory effects of serotonin and testosterone on the development of the LHRH producing system of the rat brain during the prenatal period of development].

We have performed radioimmunoassay of LHRH in rostral and septal-preoptic brain regions, as well as in mediobasal hypothalamus of male and female fetuses at day 21 of the prenatal period after the injection to pregnant females on days 11-20 of gestation of either p-chlorophenylalanine (PCPA) or of a combination of PCPA with ethane-1,2-dimethane sulfonate (EDS). Control animals received the injection of the same volume of physiological saline. In the control fetuses, both males and females, the level of LHRH in the rostral brain region was significantly lower than in the septal-preoptic region. The administration of PCPA increased the level of LHRH in the rostral brain region and decrease it in the septal-preoptic region, the effect being more prominent in males. When EDS was administered on the background of PCPA administration, sex-related differences in the level of LHRH in the studied brain regions were no longer present. It is proposed that serotonin stimulates migration of LHRH neurons in rostral-caudal direction, and this effect of serotonin is more significant in males, since it is potentiated by testosterone.