[Morphokinetic effect of PMSG and sex steroids on parts of the cerebral-hypophyseal-gonadal axis of anestrous sheep].

The action of gonadotropins and of sexual steroids on links of the cerebro-hypophyseo-gonadal axis can be morphologically quantified in sheep. In that context, karyovolumetry is a highly dependabel and information-yielding quantitative morphological method. In studies conducted with anoestrous sheep and described in this paper that method has helped to detect an inhibitory effect of PMSG and progesterone upon the activity of neurons of the medial preoptic nucleus of the hypothalamus. The two sexual steroids produced even stronger inhibition of neuronal activity of the arcuate nucleus of the hypothalamus. Such results, when evaluated and re-used under the adequate test conditions might be helpful in identifying structures of central nervous disorders along the cerebro-hypophyseo-gonadal axis and produce reliable information on acting points or general action (activation or inhibition) of active substances as well as on the course of control and regulatory mechanisms.