Gestational changes in the progesterone and prostaglandin F levels of the guinea-pig.
In 87 guinea-pigs the gestational changes were measured in the progesterone (P) and prostaglandin F (PGF) levels of the peripheral and uterine vein plasmas, ovaries, uterus, placenta, fetal membranes and amniotic fluid. In the ovaries, the peripheral and uterine vein plasma, placenta and uterus, P-concentrations increase during early pregnancy and after a plateau decrease significantly as term approaches. In contrast, the uterine-vein PGF-levels remain low throughout pregnancy and only increase near term. Thus, in the guinea-pig, as in the classic species of P-action, normal pregnancy is characterized by high P and low PGF levels and labor by low P and high PGF levels. Of special interest are the additional findings that in the guinea-pig the uterine tissue P-levels are only a fraction of the peripheral plasma levels and the placental PGF-levels far exceed those of the uterus and fetal membranes. To promote the biological interpretation of the endogenous changes in the regulatory profile of the pregnant guinea-pig, current studies examine the functional consequences of the experimentally induced changes in P and PGF-levels.
D000818:Animals; D005260:Female; D006168:Guinea Pigs / Q000502:physiology*; D008098:Litter Size; D010053:Ovary / Q000378:metabolism; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011270:Pregnancy, Animal; D011374:Progesterone / Q000378:metabolism*; D011460:Prostaglandins F / Q000378:metabolism*; D013997:Time Factors; D014599:Uterus / Q000378:metabolism
D011460:Prostaglandins F; D011374:Progesterone