Prostaglandins F in uterine tissue and venous plasma of ewes with intrauterine devices.

Levels of prostaglandins F (PGF) in uterine tissues and in uterine and peripheral plasma from ewes with and without IUD's were examined. Mature ewes were laparotomized on day 2 of the estrous cycle. Fifteen ewes with a corpus luteum on only one ovary were assigned at random to either a treated group (10 ewes) which received an intrauterine device (IUD) in each uterine horn or to a control group (five ewes). Twelve ewes had a corpus luteum on each ovary and received at random an IUD in one uterine horn (eight ewes) or a sham operation (four ewes). Blood was collected from a major vein of each uterine horn on day 5. Uteri were removed and the uterine horns were separated and dissected into caruncular and intercaruncular endometrium and myometrium. Prostaglandins F were extracted with ethyl acetate, separated by column chromatography on silicic acid and quantified by radioimmunoassay. An IUD in one or in both uterine horns resulted in higher concentrations (ng/ml) of PGF in uterine venous plasma from both horns