Reduction of hypercholesterolemia and proteinuria in nephritic rats by low-meat-protein diets

The effects of low-meat-protein diets on hypercholesterol-emia and proteinuria were studied in rats with nephrotoxic serum nephri-tis. After an injection of nephrotoxic serum, rats were given either a 20% meat-protein diet (20M), an 8.5%-meat-protein diet (8.5M), or a valine-(0.05%)-supplemented 8.5%-meat-protein diet (8.5MV) for 12 days. Urinary protein excreted from the 20M-fed, nephritic control rats in-creased rapidly and linearly during the initial 3 days, and thereafter the high excretion rate was maintained for up to 12 days. Two low-meat-protein diets (8.5M, 8.5MV) commenced to suppress proteinuria 3 days after feeding and the suppression was preserved during the rest of the experimental periods. Compared with the 20M, both low-meat-protein diets significantly improve hypercholesterolemia induced in this nephrit-ic model. These two diets significantly enhanced the fecal excretion of neutral sterols. They caused neither fatty liver nor severe growth retarda-tion. These effects of 8.5MV were identical to those of 8.5M. The results suggest that low-meat-protein feeding, without amino acid supplementa-tion, improves hypercholesterolemia and proteinuria in nephritis without severe protein malnutrition. The results also suggest that the hypochole-sterolemic effect of the low-meat-protein diets may be, at least in part, attributed to increased fecal excretion of steroids.