Journal of Applied Physiology, Vol 49, Issue 1 42-44, Copyright © 1980 by American Physiological Society
Acute small animal preparation--suitable for fetal metabolic studies?
J. A. Lemons, R. Perez, R. L. Schreiner and E. L. Gresham
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.
