title: Mechanism of action of an orally active PGE1-analogue in pregnant guinea-pigs.
abstract: At the 43rd day of pregnancy 6 Experimental guinea-pigs were treated orally with the PGE1-analogue, CP 48,630 (Pfizer), while 6 animals served as vehicle Controls. An average dose of 1.5 mg CP 48,630 compromized the conceptus and provoked abortion in 6.6 +/- 1.4 hours in all 6 Experimental guinea-pigs. The vehicle Controls, with all pregnancies continuing intact, had high P-levels in peripheral and uterine vein plasma, ovaries, placenta and uterine tissue and low PGF-levels in the uterine vein plasma. In contrast, in the Experimental animals the P-levels were significantly reduced and the PGF-levels elevated. Thus, the "PG-Impact" rapidly tipped the regulatory balance of pregnancy, compromized the conceptus (all fetuses were dead and the placentae discolored), and provoked the evolution of uterine activity culminating in abortion.
mesh_terms: D000028:Abortion, Induced; D000284:Administration, Oral; D000818:Animals; D005260:Female; D006168:Guinea Pigs; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D011459:Prostaglandins E, Synthetic / Q000378:metabolism*; D011460:Prostaglandins F / Q000097:blood; D014599:Uterus / Q000187:drug effects*
chemical_list: D011459:Prostaglandins E, Synthetic; D011460:Prostaglandins F; D011374:Progesterone; C029506:CP 48630