THE EFFECT OF EXCESS DIETARY SUCROSE ON GROWTH, BLOOD-PRESSURE, AND METABOLISM IN DEVELOPING SPRAGUE-DAWLEY RATS

To determine the effects of sucrose-enriched feeds on somatic growth, blood pressure development, and insulin-stimulated glucose metabolism, Sprague-Dawley rat pups (n = 94) were randomly assigned at weaning (3 wk) to a control diet (15% sucrose, by calories, n = 48) or an isocaloric diet in which starch is replaced by sucrose (66% sucrose, by calories, n = 46). Weight and blood pressure were followed until 13 wk. Chronic catheters were placed in a subset of male animals (n = 13), fasting glucose production was measured, and euglycemic hyperinsulinemic clamps were performed while the rats were in the conscious, nonstressed state. There was no difference in weight gain between control and sucrose rats in each sex group. Blood pressure in sucrose rats was significantly higher than in control rats after 4 wk of diet (7 wk of age,p < 0.001) in both sex groups and persisted for the duration of sucrose-enriched feeds. Insulin resistance was confirmed in sucrose rats with the euglycemic hyperinsulinemic cramp technique. In juvenile rats that have no genetic predisposition to hypertension, excess dietary sucrose induced high blood pressure without obesity. Sucrose feeding also induced insulin resistance. The sucrose-fed Sprague-Dawley weanling rat provides a model of diet-induced juvenile-onset hypertension with insulin resistance.