title: Effects of LH-RH and des-Gly10[D-Ala6]LH-RH-ethylamide on plasma gonadotropin levels and oocyte maturation in adult female coho salmon (Oncorhynchus kisutch).
abstract: Plasma gonadotropin (GtH) levels and state of oocyte development were determined in adult female coho salmon following single intraperitoneal injections of LH-RH or its superactive analog des-Gly10[D-Ala6]LH-RH-ethylamide (LH-RHA DAla6). The peptides injected at dosages of 1.0 or 0.2 mg LH-RH and 0.2 or 0.02 mg LH-RHA DAla6/kg bw elevated plasma GtH by 1.5 hr postinjection. The response to the analog was of longer duration. Plasma GtH levels returned to basal levels 24 hr following LH-RH injection while elevated plasma GtH levels were maintained for at least 96 hr in response to the analog. Only those fish injected with LH-RHA DAla6 showed an accelerated rate of germinal vesicle breakdown (GVBD). Based on their relative effects on GVBD, LH-RHA DAla6 has at least 50 times the biological potency of LH-RH in adult female coho salmon.
mesh_terms: D000818:Animals; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology*; D006062:Gonadotropins / Q000097:blood*; D007700:Kinetics; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development*; D010063:Ovum / Q000254:growth & development*; D012474:Salmon / Q000502:physiology*
chemical_list: D006062:Gonadotropins; D007987:Gonadotropin-Releasing Hormone; C010661:surfagon