Inhibition of luteal function by oxytocin antagonist in goats (Capra hircus).
Early corpus luteum development in nonpregnant and pregnant goats was characterized by a steady increase in peripheral plasma concentrations of progesterone and a high release of prostacyclin (PGI-2) but low release of prostaglandin F-2 alpha (PGF-2 alpha). Jugular administration of oxytocin antagonist (OXA) (0.2 microgram/kg/day) on the day of oestrus and for 3 days thereafter to cyclic and mated goats, significantly (P less than 0.001) inhibited progesterone and prostaglandin secretion and reduced conception rate. Co-administration of PGI-2 (200 micrograms/day) with OXA resulted in a steady increase of progesterone and establishment of pregnancy, but co-administration of PGF-2 alpha (175 micrograms/day) with OXA had no effect. It is suggested that oxytocin is required for early development of the corpus luteum and such effects may be mediated via PGI-2 production.
Homeida
A M
AM
College of Veterinary Medicine and Animal Resources, King Faisal University, Saudi Arabia.
Al-Eknah
M M
MM
D000818:Animals; D003338:Corpus Luteum / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D003864:Depression, Chemical; D015237:Dinoprost / Q000097:blood / Q000494:pharmacology; D011464:Epoprostenol / Q000097:blood / Q000494:pharmacology; D004971:Estrus / Q000097:blood / Q000187:drug effects*; D005260:Female; D006041:Goats / Q000502:physiology*; D010121:Oxytocin / Q000037:antagonists & inhibitors*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000097:blood / Q000187:drug effects*; D011374:Progesterone / Q000097:blood; D014668:Vasotocin / Q000031:analogs & derivatives* / Q000494:pharmacology
D011374:Progesterone; D010121:Oxytocin; C065085:vasotocin, 1-(beta-mercapto-beta,beta-diethylpropionic acid)-(OEt-Tyr)(2)-Orn(8)-; D015237:Dinoprost; D011464:Epoprostenol; D014668:Vasotocin