Abstract
PREVIOUS evidence suggests that the uterus is a controlling factor in luteolysis in several species. Hysterectomy, as first shown by Loeb (1923) in the guinea pig and subsequently in sheep (Wiltbank and Casida, 1956; Rowson and Moor, 1964; Kiracofe and Spies, 1964), cattle (Wiltbank and Casida, 1956; Anderson, Neal and Melampy, 1962) and swine (du Mesnil du Buisson and Dauzier, 1959; Spies et al., 1960; Anderson, Butcher and Melampy, 1961), prolongs the life span of the corpus luteum. Furthermore, as described in a review by Anderson, Bland and Melampy (1969), the removal or destruction of endometrial tissue alone has been associated with induced maintenance of the corpus luteum. Aqueous extracts of bovine endometrium (Duby et al., 1969) and ovine endometrium (Caldwell, Moor and Lawson, 1968) collected from cycling animals on day 14 and 15 caused luteolysis when injected into the hysterectomized-pseudopregnant hamster. This assay was first described by Mazer and Wright (1968). Lukaszewaska and Hansel (1970) have reported luteolytic activity in partially purified bovine endometrial extracts from uteri collected on day 10 to 13 of the estrous cycle. Copyright © 1972. American Society of Animal Science . Copyright 1972 by American Society of Animal Science.