COMPARISON OF THE METABOLIC CHANGES IN RATS WITH HYPERTENSION SECONDARY TO FRUCTOSE FEEDING OR RENAL-ARTERY STENOSIS

Hypertension was induced in rats by either renal artery stenosis or a fructose-enriched diet, and the consequent changes in plasma glucose, insulin, and triglyceride (TG) concentrations, and the steady-state pl asma insulin (SSPI) and glucose (SSPG) concentrations in response to a 180-min continuous infusion of glucose and insulin in these two group s of hypertensive rats, were compared to values in a sham-operated gro up with normal blood pressure. Mean (+/- SEM) blood pressure was signi ficantly higher than the control values (121 +/- 3 mm Hg) at the end o f the study in rats with renal artery stenosis (178 +/- 13 mm Hg) and fructose-fed rats (151 +/- 5 mm Hg), whereas left ventricular weight w as only significantly (P < .01) higher in rats with renal artery steno sis. Plasma glucose concentration was the same in all three groups, bu t fructose-fed rats had significantly higher plasma insulin (59 +/- 7 mu U/mL) and TG (317 +/- 48 mg/dL) concentration than either sham-oper ated rats (30 +/- 4 mu U/mL and 121 mg/dL) or rats with renal artery s tenosis (34 +/- 5 mu U/mL and 124 +/- 14 mg/dL). Although SSPI concent rations were similar (similar to 250 mu U/mL) in all three groups of r ats, SSPG concentrations were significantly higher (P < .01) in the fr uctose-fed rats (187 +/- 10 mg/dL) than in either sham-operated normot ensive rats (120 +/- 6 mg/dL) or hypertensive rats with renal artery s tenosis (133 +/- 4 mg/dL). Thus, insulin resistance, hyperinsulinemia, and hypertriglyceridemia developed in rats with fructose-induced hype rtension, whereas none of these changes were seen in rats with renal a rtery stenosis.