[Changes in the basal secretion of gonadotropins and the luliberin content of the hypothalamus of male rats administered catecholamines locally into the hypothalamic nuclei].

The effect of pharmacological agents (alpha-adrenoblockers alpha-adrenergic stimulators) and dopamine (DA) on LH secretion as well as the effect of local administration of noradrenaline (NA) and DA into the preoptic area (PA) or arcuate nuclei (ARC) on the LH-RH content in hypothalamic nuclei and blood LH and FSH concentration were investigated in experiments on male rats. An inhibitory effect of alpha-adrenoblockers on LH secretion was shown. This effect was reversed by the administration of stimulators DA or alpha-adrenoreceptors. Differences in the type of changes in LH-RH concentration and LH and FSH levels in response to NA and DA administration were established: a stimulating NA effect on the secretion of gonadotropins at the PA level was noted whereas a stimulating DA effect was more noticeable at the ARC level. Catecholamine effects were steroid-related. A conclusion was made that the regulation of tonic secretion of gonadotropins was not restricted to the mediobasal hypothalamus only: the anterior hypothalamus was also involved in control.