Dietary-induced hyperlipidemia and renal function in the uremic rat.

Rats made uremic by 2-stage 5/6 nephrectomy and sham-operated control animals were fed either a normal laboratory chow, a high-sucrose (60%) or a high-fat (10% cholesterol; 20% olive oil) diet, all containing 21% protein and identical amounts of electrolytes, vitamins and trace elements. Serum creatinine levels remained unchanged in the control animals but rose in the 5/6 nephrectomised uremic animals by a factor of 2.7 from a mean of 0.44 +/- 0.05 mg/dl to 1.20 +/- 0.11 mg/dl at 8 weeks, without differences between the dietary groups. During 8 weeks of dietary regimen the high-sucrose and high-fat diets induced significant hypertriglyceridemia, generally similar in control and uremic rats. The uremic animals on a high-sucrose and high-fat diet had the most pronounced rise in serum triglycerides, 331.5 +/- 89.0 and 298.0 +/- 45.0 mg/dl, respectively (control: 159.9 +/- 14.0 mg/dl). After 4 and 8 weeks, only the animals on the high-fat diet had significant hypercholesterolemia, most pronounced in the uremic animals (356 +/- 56.3 mg/dl; control: 71.6 +/- 12.9 mg/dl). The animals in the latter group also had significant proteinuria and renal histologic abnormalities consisting of xanthoma-like glomerular lesions, infiltrates and fibrosis not seen in the other groups of animals. These data indicate that dietary-induced hyperlipidemia of short duration causes or aggravates renal damage in the rat with mild-moderate uremia, induced by ablation.