Evidence for a possible foetal control of prostaglandin release from the pregnant rat uterus in vitro.
The release of prostaglandin-like material and these spontaneous contractions of individual horns from the pregnant rat uterus in vitro have been studied on day 22 of pregnancy - the expected day of delivery. Removal of foetuses (retaining placentae in utero) from one or both uterine horns on day 16 or 17 significantly reduced prostaglandin F release and spontaneous activity. Rats which had been made unilaterally pregnant after ligation of one uterine horn, exhibited a decrease in prostaglandin F output from both horns. Uterine activity and prostaglandin release were increased in quiescent uteri by the addition of arachidonic acid (5 mug/ml) or phospholipase A (160 mu./ml); the effects were abolished by indomethacin (20 mug/ml). However, the stimulation of uterine activity by PGF2alpha (30-60 ng/ml) was not affected by indomethacin. It is concluded that the release of prostaglandins from the pregnant rat uterus in vitro at term is related to the presence of viable foetuses.
D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D005260:Female; D005333:Fetus / Q000502:physiology*; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008026:Ligation; D010740:Phospholipases / Q000494:pharmacology; D010920:Placenta; D011247:Pregnancy; D011270:Pregnancy, Animal; D011448:Prostaglandin Antagonists; D011453:Prostaglandins / Q000378:metabolism*; D011460:Prostaglandins F / Q000378:metabolism / Q000494:pharmacology; D011863:Radioimmunoassay; D051381:Rats; D013268:Stimulation, Chemical; D013997:Time Factors; D014590:Uterine Contraction / Q000187:drug effects; D014599:Uterus / Q000378:metabolism* / Q000601:surgery
D001095:Arachidonic Acids; D011448:Prostaglandin Antagonists; D011453:Prostaglandins; D011460:Prostaglandins F; D010740:Phospholipases; D007213:Indomethacin