Total body-glucose turnover in normal and intra-uterine growth-retarded neonatal piglets.

1. Because studies of the metabolic problems of the human intra-uterine growth-retarded neonate are limited by ethical considerations we have used the intra-uterine growth-retarded piglet as an animal model. Total body-glucose kinetics were measured in 16 intra-uterine growth-retarded and 11 normal piglets from the same litters with [3H]glucose as a tracer. 2. The intra-uterine growth-retarded animals had marginally smaller brains than their normal littermates, but substantially smaller livers. Liver weight was reduced in proportion to body weight. 3. Total body-glucose turnover rate was significantly lower (P less than 0.001) in the intra-uterine growth-retarded animals in comparison with their normal littermates, but was appropriate for their smaller body and liver weights. Brain weight was only slightly reduced in the intra-uterine growth-retarded group so that glucose turnover adjusted to a common brain weight was significantly lower (P less than 0.001) in these animals. 4. Total body-glucose pool size was lower in the intra-uterine growth-retarded animals (P less than 0.01), but was appropriate for their body and liver weights. It was significantly reduced in relation to brain weight (P less than 0.001). 5. Resting plasma glucose concentration was lower in the intra-uterine growth-retarded animals (P less than 0.001). There was no relationship between concentration and turnover in either group. 6. It is suggested that the observed differences in total body-glucose turnover may be associated with profound differences in cerebral metabolism in the intra-uterine growth-retarded animals.