AJP - Endocrinology and Metabolism, Vol 251, Issue 4 448-E456, Copyright © 1986 by American Physiological Society

ARTICLES

Effects of fetal insulin infusion on glucose kinetics in pregnant sheep: a compartmental analysis

C. A. Bloch, W. Banach, K. Landt, S. Devaskar and M. A. Sperling

A three-compartment model, consisting of fetus (F), uteroplacenta, and mother (M) was applied to quantitate the effects of fetal hyperinsulinemia on glucose kinetics in pregnant sheep late in gestation. The approach combines the Fick principle with isotope dilution of differentially labeled glucose isotopes, infused simultaneously to F [U-14C]- and M [2-3H]glucose. In the basal state, rates of umbilical glucose uptake (8.37 +/- 0.98 mg/kg per min) and fetal glucose utilization (7.38 +/- 1.13) were equivalent (mean +/- SE; n = 12). When fetal insulin was increased from 13.7 +/- 2.2 to a plateau of approximately 100 microU/ml, arterial glucose decreased from 18.9 +/- 0.8 to a new steady state of approximately 13 mg/dl (P less than 0.001). Whereas umbilical glucose uptake increased at 90 min and remained elevated thereafter (P less than 0.01), fetal glucose utilization increased only transiently at 60 min by 1.9 +/- 0.8 mg/kg per min (26%; P less than 0.05) and then returned to base line. Insulin's persistent effect, however, was evident from the sustained doubling of the glucose clearance rate from 39.3 +/- 5.9 to 66.6 +/- 10.5 ml/kg per min (P less than 0.005). No endogenous fetal glucose production was evident throughout the experiments. Maternal glucose production and utilization remained unchanged, although there was a small decline in M glucose concentration and an increase in glucose transfer from M to the uteroplacenta and F, from 33.9 +/- 8.1 to 48.1 +/- 7.0 mg/min at 60 min (P less than 0.01 by paired analysis). We conclude that fetal hyperinsulinemia initially lowers glucose concentration by transiently increasing fetal glucose utilization.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				J. He, M. Thamotharan, and S. U. Devaskar Insulin-induced translocation of facilitative glucose transporters in fetal/neonatal rat skeletal muscle Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2003; 284(4): R1138 - R1146. [Abstract] [Full Text] [PDF]

				U. G. Das, R. E. Schroeder, W. W. Hay Jr., and S. U. Devaskar Time-dependent and tissue-specific effects of circulating glucose on fetal ovine glucose transporters Am J Physiol Regulatory Integrative Comp Physiol, March 1, 1999; 276(3): R809 - R817. [Abstract] [Full Text] [PDF]