title: Inhibitors of the luteinizing hormone-releasing hormone based upon modifications in the 2, 3, and 6 positions.
abstract: [Leu2,Leu3,D-Ala6]-LH-RH (less than Glu-Leu-Leu-Ser-Tyr-D-Ala-Leu-Arg-Pro-Gly-[NH2) and [Val2,Leu3,D-Ala6]-LH-RH completely inhibited the release of LH and FSH induced by 0.3 ng/ml of medium of LH-RH on isolated rat pituitaries, at a dosage of 10 mug. [Leu2,Val3,D-Ala6]-LH-RH and [Val2,Val3,D-Ala6]-LH-RH also completely inhibited this response but were one-tenth as active as [Leu2,Leu3,D-Ala6]-LH-RH. All of the analogs were devoid of agonist activities. The incorporation of the D-Ala residue in position 6 into the [Leu2,Leu3]-LH-RH sequence, therefore, increased the inhibition potency as much as tenfold.
mesh_terms: D000818:Animals; D003864:Depression, Chemical; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors*; D066298:In Vitro Techniques; D007986:Luteinizing Hormone / Q000378:metabolism; D009842:Oligopeptides / Q000138:chemical synthesis / Q000494:pharmacology*; D010902:Pituitary Gland / Q000378:metabolism; D051381:Rats; D013329:Structure-Activity Relationship
chemical_list: D009842:Oligopeptides; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone