Growth and metabolic parameters in pups of undernourished lactating rats

Abstract

Effects of reduced nutrition during postnatal development were studied by measuring body weight, plasma corticosterone, corticosterone-binding globulin (CBP), and metabolic parameters (plasma glucose and body composition) in preweanling Long Evans rat pups. Control litters consisted of dams that were fed chow ad lib while restricted dams were provided 1/3 the amount of chow given controls (25-30 g/day). At 11 days, body weight of the restricted pups dropped below that of controls. Percent body lipid, plasma corticosterone and glucose of restricted pups were lower than controls. Binding capacity of CBP in controls increased without a change in binding affinity (Kd). By contrast, binding capacity of CBP of restricted pups never matched that of controls but the Kd increased. Nutritional deprivation during lactation affected production of CBP that effectively reduced the biological activity of corticosterone in circulation. Deprived of an effective cellular response to an impoverished supply of food, pups were left with little capacity to manage endogenous fuels during the growth spurt that normally occurs during the suckling period.