Interaction of hCG and Lutalyse on steroidogenesis of bovine luteal cells.
This study was designed to examine the ability of in vivo administration of human chorionic gonadotropin (hCG, 4000 IU) to alter the effects of Lutalyse (PGF2 alpha, 10 mg) in the cow. hCG significantly increased plasma progesterone concentration in midcycle cows (P less than 0.01), but these elevated levels were not maintained in the presence of Lutalyse (P less than 0.05). Responsiveness of luteal cells in vitro to luteinizing hormone (LH) (100 ng/ml), prostaglandin F2 alpha (PGF2 alpha) (1 microgram/ml), dibutyryl cyclic AMP (dbcAMP) (10 mM) and PGF2 alpha (1 microgram/ml) + dbcAMP (10 mM) during a 2 h incubation was significantly reduced following in vivo treatment with Lutalyse when compared to in vivo untreated animals. In conclusion, the luteotropic effects of hCG were incapable of preventing Lutalyse-induced regression of the corpus luteum, and treatment of animals with hCG prior to Lutalyse administration could not prevent the significant decrease in responsiveness of luteal cells in vitro.
Litch
S J
SJ
Department of Animal and Nutritional Sciences, University of New Hampshire, Durham 03824.
Condon
W A
WA
D000020:Abortifacient Agents, Nonsteroidal / Q000378:metabolism; D000818:Animals; D002417:Cattle; D006063:Chorionic Gonadotropin / Q000378:metabolism*; D003338:Corpus Luteum / Q000378:metabolism*; D015237:Dinoprost / Q000031:analogs & derivatives*; D004347:Drug Interactions; D005260:Female; D008184:Luteal Cells / Q000378:metabolism*; D011374:Progesterone / Q000096:biosynthesis*; D011461:Prostaglandins F, Synthetic / Q000378:metabolism*
D000020:Abortifacient Agents, Nonsteroidal; D006063:Chorionic Gonadotropin; D011461:Prostaglandins F, Synthetic; D011374:Progesterone; D015237:Dinoprost; C010714:dinoprost tromethamine