The effect of diets containing 8.5%, 21% or 40% protein on growth, urinary albumin excretion and serum albumin concentration was determined in rats with Heymann nephritis and in non-nephrotic control animals. Urinary albumin excretion was greater in nephrotic rats with each increment in dietary protein intake, and serum albumin concentration tended to be in nephrotic rats fed 40% protein. Albuminuria decreased spontaneously and serum albumin concentration increased in nephrotic rats fed 8.5% protein for 25 days. Enalapril treatment caused a further reduction in urinary albumin excretion and an increase in serum albumin concentration in nephrotic rats fed 8.5% protein. Albuminuria did not decrease nor did serum albumin concentration increase in nephrotic rats fed 40% protein without enalapril treatment, but enalapril caused a significant reduction in urinary albumin excretion and an increase in serum albumin concentration in nephrotic rats fed either 8.5% or 40% protein. The rate of growth in normal rats was greatest when they were fed 21% protein, compared to either 8.5% or 40% protein. Growth rate was significantly reduced in nephrotic rats, regardless of dietary protein intake and regardless of treatment with enalapril, but the 21% protein diet still induced the most rapid rate of growth. Growth rate was not significantly different in nephrotic rats fed either 40% or 8.5% protein. The difference in weight between pair fed nephrotic and control animals fed 21% protein was due to a decrease in carcass and skin weight in nephrotic animals. Carcass protein was significantly reduced in the nephrotic animals, and carcass saponafiable fat tended to be reduced. Carcass, as a fraction of total body weight, decreased significantly in nephrotic rats fed 40% protein, and both liver and kidney weight increased. As a result, dietary protein supplementation resulted in no increase in total carcass protein in nephrotic rats. Saponafiable fats were significantly reduced in nephrotic rats fed 40% protein, and this decrease in saponafiable fats was unaffected by enalapril treatment. Derangements both in growth and in body composition of nephrotic rats prove resistant to dietary protein supplementation and are not corrected by the addition of enalapril, despite the salutary effect on albumin metabolism. There is no obvious beneficial effect of high protein diets as a therapy for the protein depleted state resulting from the nephrotic syndrome in rats. White rats fed an 8.5% protein diet exhibit the best preservation of albumin stores, they fail to grow at all.
|Original language||English (US)|
|Issue number||SUPPL. 27|
|State||Published - 1989|
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