Hyperfiltration due to amino and keto acid supplements of low-protein diets: influence on proteinuria.

In 12 male 5/6 nephrectomized Sprague-Dawley rats we analyzed the influence of commercially available amino/keto acid supplements on proteinuria. The addition of different supplements to an 8% protein diet resulted in an increase of preexisting proteinuria. Keto acids per se do not seem to cause a remarkable degree of proteinuria/hyperfiltration. Our data underline the importance of the protein content of a low-protein diet and the composition of amino/keto acid supplements, as these factors per se can cause hyperfiltration and might accelerate progression of chronic renal failure.