title: Gonadotropin-releasing activity of two highly active and long-acting analogs of luteinizing hormone-releasing hormone after subcutaneous, intravaginal, and oral administration.
abstract: The gonadotropin-releasing activities of two synthetic analogs of luteinizing hormone-releasing hormone (LH-RH), D-Ala6-des-Gly10-LH-RH ethylamide and D-Leu6-des-Gly10-LH-RH ethylamide were evaluated in immature female rats after subcutaneous, intravaginal, and oral administration. Maximal peaks of serum LH and follicle-stimulating hormone (FSH) levels after administration of both analogs by any of the three routes were obtained at 2 hours. Therefore, serum gonadotropin levels declined slowly, so that at 6 hours LH levels had returned to base line values, whereas FSH levels remained elevated for up to 10 hours. The integrated serum gaondotropin levels after LH-RH and both analogs over a 10-hour period indicated that D-Leu6-des-Gly10-LH-RH EA and D-Ala6-des-Gly10-LH-RH EA released more LH and FSH than did the LH-RH decapeptide. The intense and long-acting properties of these analogs in releasing LH and FSH suggest the possibility that they may be more useful therapeutically than LH-RH.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives*; D006728:Hormones / Q000494:pharmacology*; D007279:Injections, Subcutaneous; D007986:Luteinizing Hormone / Q000097:blood; D051381:Rats; D013488:Suppositories; D014621:Vagina
chemical_list: D006728:Hormones; D013488:Suppositories; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone