title: Time-dependent decrease of pituitary response to LH-RH after chronic treatment of intact female rats with ethinyloestradiol and norethindrone.
mesh_terms: D000818:Animals; D010122:Cystinyl Aminopeptidase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004971:Estrus; D004997:Ethinyl Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D007987:Gonadotropin-Releasing Hormone; D007031:Hypothalamus / Q000201:enzymology; D007275:Injections, Intravenous; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D009640:Norethindrone / Q000008:administration & dosage / Q000494:pharmacology*; D010903:Pituitary Gland, Anterior / Q000201:enzymology / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D013997:Time Factors
chemical_list: D007987:Gonadotropin-Releasing Hormone; D004997:Ethinyl Estradiol; D007986:Luteinizing Hormone; D010122:Cystinyl Aminopeptidase; D009640:Norethindrone