Effect of chronic ipsilateral or contralateral intrauterine infusion of prostaglandin E1 (PGE1) on luteal function of unilaterally ovariectomized ewes.

Chronic intrauterine infusions of either vehicle or 500 microgram PGE1 were given every four hours either adjacent to or opposite to the corpus luteum of unilaterally ovariectomized ewes from day 10 through day 25 postestrus or until subsequent estrus. PGE1 maintained luteal function (p less than 0.01) and delayed the return to estrus (p less than 0.01) only in ewes when chronically infused into the uterine horn adjacent to the ovary with a corpus luteum. It is concluded that PGE1 could be an antiluteolysin of early pregnancy since it delayed luteal regression only through a local but not a systemic route which is also the same situation as that reported for the presence of an embryo.