Intrauterine infusion of BQ-610, an endothelin type A receptor antagonist, delays luteolysis in dairy heifers.

摘要: Three separate in vivo experiments were conducted to evaluate the putative role of endothelin-1 (ET-1) during luteal regression heifers. In Experiment 1, a single intraluteal injection 500 microg BQ-610 [(N,N-hexamethylene) carbamoyl-Leu-D-Trp (CHO)-D-Trp], highly specific endothelin A (ETA) receptor antagonist, did not diminish decline plasma progesterone following exogenous 25 mg prostaglandin F2 alpha (PGF2alpha) administered at midcycle estrous cycle. 2, six intrauterine infusions given every 12 h on days 16-18 delayed spontaneous luteolysis, as evidenced by an extended elevation (P=0.054) concentration. 3, heifers or saline 16-19, and peripheral blood samples collected from day 11 16 (before infusion), hourly 16-19 (during 20-25 (after infusion). treated had markedly higher (P or=0.05) between treatments. These results indicate that antagonism ETA can delay functional supports theory ET-1 regulates function ruminants.