Effects of prostaglandin E 2 (PGE 2) on estradiol-17β-induced luteolysis in the nonpregnant ewe

Abstract

Fifteen ewes were assigned as they came into estrus to the following randomized treatment groups: 1) Vehicle (1 ml corn oil + vehicle Na 2CO 3 buffer), 2) Estradiol-17β + vehicle and 3) Estradiol-17β + PGE 2 (500 μg) in Na 2CO 3 buffer (5 ewes/treatment group). Prostaglandin E 2 was given through an intrauterine cannula every four hours from days 8 through 15 postestrus. PGE 2 prevented a luteolytic dose of estradiol-17β given on days 9 and 10 from causing a precious luteolysis. PGE 2 maintained concentrations of progesterone in peripheral blood (days 8 through 15) and weights and concentrations of progesterone in corpora lutea on day 15 postestrus of ewes receiving estradiol-17β. It is concluded that chronic intrauterine infusions of PGE 2 can prevent an estradiol-17β-induced premature luteolysis.