AJP - Regulatory, Integrative and Comparative Physiology, Vol 247, Issue 5 755-R760, Copyright © 1984 by American Physiological Society
Comparison of lactate and glucose metabolism in the developing porcine placenta
T. G. Ramsay, J. A. Sheahan and R. J. Martin
The present experiment was conducted to determine whether lactate is an
important metabolic substrate for the developing porcine placenta. Pregnant
gilts were anesthetized with pentobarbital sodium (5 mg/kg) at 65, 85, or
110 days of gestation and underwent an abdominohysterectomy. Fetal and
maternal placental tissues were obtained and isolated for enzyme analysis
and tissue incubations. Tissues were incubated for 2 h in Krebs-Ringer
bicarbonate buffer containing 10 mM glucose, 1.0 mM Na-palmitate, 2.0 mM
L-lactate, and 2% albumin. The incorporation of glucose or lactate into
CO2, total lipids, and fatty acids was examined by radioactive tracers.
Lactate was shown to be at least as important a substrate as glucose for
utilization through these metabolic pathways in both the fetal and maternal
placentas during gestation. This ability to metabolize lactate may serve as
a conservation mechanism to spare other nutrients for transfer to the
fetus. Additionally, analysis of enzyme and incubation data indicated that
the fetal and maternal placenta follow different developmental patterns,
implying the origins for (or mechanisms of) regulation of these two tissues
may differ.
