A cooperative action of endothelin-1 with prostaglandin F2α on luteal function in the cow

摘要: Abstract Prostaglandin F 2α (PGF ) is the primary luteolysin in cow, and luteal endothelin-1 (ET-1) interacts with PGF during process of luteolysis. In contrast, a developing corpus luteum (CL) refractory to exogenous administration . Thus, present study was aimed investigate functional relationship between ET-1 mid-CL -sensitive) early-CL -refractory). model, cows ( n =6/treatment) were assigned receive one five types treatments on day 10 estrous cycle: (1) an injection saline; control, (2) 500μg analogue (sufficient dose induce luteolytis); full-PG, (3) intraluteal 0.25mg ET-1; ET-1, (4) 125μg (insufficient 1/4PG or (5) after insufficient analogue; 1/4PG/ET. two 5 sufficient PG =5) ; PG/ET =7). 1/4PG/ET resulted rapid reduction progesterone (P) concentrations similar that full-PG from next day. However, levels P (1.5–2.5ng/ml) kept significantly higher than induces depression secretion vivo mid phase supporting concept local mediator luteolysis cow. The result further indicates not only PG-refractory but also ET-1-refractory.