Leg Metabolism of Amino Acids and Ammonia in Patients with Chronic Renal Failure

Publisher Website
Google Scholar
Abstract
Leg metabolism of amino acids and ammonia in the postabsorptive state was evaluated in 10 patients with chronic renal failure (CRF) and in 10 patients with normal renal function (controls) by measuring the arterial-femoral venous (A-FV) differences for free amino acids and ammonia. Protein breakdown in peripheral tissues is not increased in patients with CRF. In CRF selective metabolic abnormalities for some amino acids are evident. While only the A-FV differences for valine, leucine and isoleucine are decreased, additional alterations are observed by relating the A-FV difference for each amino acid to that of proteolytic markers. In CRF histidine release relative to that of proteolytic markers is reduced, whereas proline and arginine release is increased. In CRF the reduced release of some amino acids, mainly branched-chain amino acids, by the leg probably affects the pattern of circulating amino acids. Both in patients and in controls a significant uptake of ammonia is observed; the ammonia uptake is related to arterial levels of this metabolite, confirming the role of peripheral tissues in removing ammonia from circulation.