BENEFICIAL-EFFECTS OF CHRONIC ADMINISTRATION OF DIETARY OMEGA-3 POLYUNSATURATED FATTY-ACIDS IN DOGS WITH RENAL-INSUFFICIENCY

Dietary supplementation with polyunsaturated fatty acids (PUFA) alters the course of experimental renal disease in rats. However, chronic re nal disease in other laboratory animals and in human beings frequently responds differently to experimental manipulations. We investigated t he effects of variations in dietary PUFA composition on the chronic co urse of induced renal disease in dogs. Two months after 15/16 nephrect omy, dogs were randomly divided into three groups of seven animals eac h. For the next 20 months, each group of dogs was fed a low-fat basal diet supplemented with one of three sources of lipid to achieve a fina l concentration of 15% added fat. Fat sources provided omega-3 PUFA (m enhaden fish oil, group FO), omega-6 PUFA (safflower oil, group SO), o r saturated fatty acids (beef tallow, group BT). Throughout the dietar y trial, the magnitude of proteinuria and the plasma concentrations of creatinine, cholesterol, and triglyceride were lower in group FO. The mean overall glomerular filtration rate was 0.89 +/- 0.18 ml/min per kilogram of body weight in group SO, a value that was significantly le ss (p < 0.05) than the corresponding values for groups BT and FO (1.21 +/- 0.18 and 1.43 +/- 0.20 ml/min/kg, respectively). Renal interstiti al fibrosis also was significantly elevated in group SO. The extents o f mesangial matrix expansion, glomerulosclerosis, and renal interstiti al cellular infiltrate were similar in groups BT and SO, but lower (p < 0.05) in group FO. We conclude that supplementation with omega-6 PUF A enhanced renal injury; supplementation with omega-3 PUFA was renopro tective.