Prostaglandin and thromboxane production by the rat uterus and ovary in vitro during the oestrous cycle

Abstract

The major prostaglandin (PG) synthesized by homogenates of the rat uterus and ovary in vitro was prostacyclin (PGI-2), reflected by the amounts of 6-oxo-PGF-1.alpha. produced. Thromboxane production by both tissues was low; appreciable quantities of PGF-2.alpha., PGE-2 and PGD-2 were produced. Prostaglandin production by the uterus was higher on day 1 (estrus) than on day 3 (diestrus), although the ratio of the amounts of the PG formed remained fairly constant for each day. There was no daily variation in the amounts of PG synthesized by the ovary. PGF-2.alpha. metabolism by the rat uterus and ovaries was low, although the ovaries had a higher metabolizing capacity than the uterus. Metabolism by the uterus was higher on day 1 than on day 3 of the cycle. The decreased production of PG by the uterus on day 3 is not due to increased metabolism.