Direct hypophysial inhibition of luteinizing hormone release by dopamine in the rabbit.

摘要: Abstract The role and site of action dopamine in regulating gonadotropin secretion remain unclear. In the present study, we investigated possibility that regulates LH by acting directly on pituitary gland rabbit. effect infusion LHRH-evoked release was determined intact stalk sectioned animals. Intravenous injection LHRH (1 μg) acutely rabbits increased peripheral plasma levels from a resting value 0.2 ng/ml to maximal values 12–14 within 10–20 min. When infused iv at dose 6.6 μg/min/kg BW 30 min before until 120 after, rise animals decreased 50–70%. However, lower (0.66 BW) or higher (66.0 BW), did not affect LHRH-induced LH. These results suggest can exert direct hypophysial inhibitory They also demonstrate is only restricted dose-range, extending an established property cardiovascular system.