title: [Age and increase in the sensitivity threshold of the tonic region of the hypothalamic sex center to inhibition by estradiol in female rats].
abstract: Estradiol-17 beta was injected into the 3rd ventricle of hemiovariectomized rats to study the sensitivity of the hypothalamic sexual centre. In aged (14--16-month-old) rats the dose of estradiol required for suppression of the compensatory ovarian hypertrophy by 50 and 100 per cent was 4--5 times greater than in young (3-month-old) rats. The results obtained suggest the age-associated increase of the threshold sensitivity of the tonic region of the hypothalamic sexual centre to estrogen suppression. These data can be used for the interpretation of the mechanism of both the age-associated elevation of gonadotropin secretion, and of the reproductive function.
mesh_terms: D000367:Age Factors; D000818:Animals; D003864:Depression, Chemical; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D051381:Rats
chemical_list: D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol
vernacular_title: Vozrastnoe povyshenie poroga chuvstvitel'nosti tonicheskoĭ oblasti polovogo tsentra gipotalamusa k tormozheniiu éstradiolom u samok krys.