Metabolic quotients and oxygen extraction across the uterus of the post-term pregnant rabbit under chronic steady-state conditions.
The extraction of oxygen by the uterus in the term rabbit has been found to be very high. During post-term pregnancy, the fetuses of the rabbit are approximately 40% larger, despite a reduction in placental weight of approximately 30%. The purpose of our study was to investigate the changes that occur in the maternal rabbit to allow survival of the fetus under these conditions. Post-term pregnancies were induced in 5 white New Zealand rabbits by injections of chorionic gonadotropin and progesterone on the 26th day of gestation. Catheters were placed surgically on day 28, and blood samples were taken daily from the femoral artery and uterine veins starting at day 31. Each sample was analyzed for pH, PCO2, PO2, oxygen capacity and saturation, glucose, beta-hydroxybutyrate, lactate and acetoacetate. Coefficients of extraction were calculated for oxygen and metabolic quotients were calculated for each substrate. These data are compared with those obtained for the term rabbit in previous studies. There was a significant increase in the coefficient of oxygen extraction in the post-term animals; however, the metabolic quotients across the uterus were not significantly different between the term and the post-term rabbit.
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D005333:Fetus / Q000033:anatomy & histology; D005865:Gestational Age; D007773:Lactates / Q000097:blood; D009929:Organ Size; D010101:Oxygen Consumption; D010920:Placenta / Q000033:anatomy & histology; D011247:Pregnancy; D011273:Pregnancy, Prolonged / Q000378:metabolism*; D011817:Rabbits; D014599:Uterus / Q000378:metabolism*
D001786:Blood Glucose; D007773:Lactates