title: Acute small animal preparation--suitable for fetal metabolic studies?
abstract: To determine the immediate effects of the "acute" experimental preparation, 11 near-term pregnant rabbits and 20 fetuses were studied. Blood samples were obtained from the maternal auricular artery, the fetal umbilical vein, and the fetal heart within 90 s of exposure of the uterus by laparotomy. Samples were assayed for pH, O2 and CO2 tension, O2 content, blood urea nitrogen, and plasma glucose. Results indicated that a pronounced fetal acidosis (primarily respiratory) had developed by the time samples were obtained. Further, fetal cardiac glucose levels were significantly elevated above umbilical vein concentrations in 7 of the 20 fetuses. In addition, maternal arterial O2 tension under light pentobarbital anesthesia was significantly less than that found in 35 unanesthetized does (52 vs. 79 Torr, P less than 0.01). All parameters measured varied over a wide range between animals. The results raise serious questions concerning the feasibility of performing and interpreting certain metabolic or cardiorespiratory studies in the acute small animal preparation.
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001806:Blood Urea Nitrogen; D005260:Female; D006863:Hydrogen-Ion Concentration; D008431:Maternal-Fetal Exchange; D008954:Models, Biological; D010100:Oxygen / Q000097:blood; D011247:Pregnancy; D011817:Rabbits
chemical_list: D001786:Blood Glucose; D010100:Oxygen