Prostaglandins E and F in uterine venous plasma in relation to peripheral plasma levels of progesterone and 20alpha-hydroxyprogesterone in the rat throughout pregnancy and parturition.
Prostaglandins E and F in uterine venous plasma and progesterone (P) and 20alpha-hydroxyprogesterone (20alpha-OH-P) in peripheral plasma were measured by radioimmunoassays throughout pregnancy and parturition in the rat. E Prostaglandins are low (approx. 2 ng/ml) and maintain a more or less constant level throughout most of the pregnancy except just before parturition when they rise to  3.8 ng/ml on day 20. F Prostaglandin levels are always higher than E prostaglandins and show distinct peaks around day 5 (5 ng/ml), day 11 (7 ng/ml), and before parturition (8.4 ng/ml). Progesterone levels are higher than 20alpha-OH-P levels throughout most of the pregnancy (day 6-20); however, during early pregnancy (day 1-5) and before parturition more 20alpha-OH-P than P is present in peripheral blood. The possible role of uterine venous prostaglandin levels in altering the 20alpha-OH-P/P ratio during pregnancy and parturition is discussed.
D000818:Animals; D005260:Female; D006908:Hydroxyprogesterones / Q000097:blood*; D049590:Postpartum Period; D011247:Pregnancy; D011270:Pregnancy, Animal; D011374:Progesterone / Q000097:blood*; D011458:Prostaglandins E / Q000097:blood*; D011460:Prostaglandins F / Q000097:blood*; D011863:Radioimmunoassay; D051381:Rats; D014599:Uterus / Q000378:metabolism*
D006908:Hydroxyprogesterones; D011458:Prostaglandins E; D011460:Prostaglandins F; D011374:Progesterone