| Abstract: | There were two groups of rats: one was injected with testosterone propionate (10 mg/kg) every 7 days starting from weaning (23 days old); the other group had gonadectomy on the same day. The levels of 5-HT and 5-HIAA were measured by spectrofluorometry. The concentrations of 5-HT in the diencephalon of the testosterone propionate injected rats decreased significantly at 45 days, tending to become reestablished at 60 days; the rest of the brain followed the same pattern, but was less pronounced. The concentrations of 5-HIAA in the diencephalon and the rest of the brain decrease throughout postnatal development, although the differences are not significant. The castrated rats showed a marked increase at 45 days and later decreased at 60 days without recovering their initial values, in both brain areas. 5-HIAA concentrations were similar to those found in the injected animals. These facts can have various interpretations: early modifications in the brain, feed-back regulation mechanisms at the level of the hypothalamus, decrease in the release of the amine or reduction of its catabolism. |
