Urea Appearance Rate Research Articles

Urea metabolism in chronic renal failure.

Urea degradation was measured during 16 experiments in 13 chronic uremic patients being treated with essential amino acids or their analogues. [(14)C]Urea was injected i.v. and the clearance of labeled urea from its volume of distribution was compared with the simultaneous renal clearance of ordinary urea, which averaged 2.0 liters/day. The difference, extrarenal clearance of urea, averaged 3.1 liters/day as compared with a previously reported mean of 18 liters/day in normal subjects. Thus urea-splitting activity in the gut of uremic subjects expressed in these terms is far less than in normal individuals. Nevertheless, the amount of ammonia N formed from urea in these patients, 3.5 g/day, is not significantly different from normal, owing to their elevated plasma urea. In the same subjects, urea appearance rate was measured as the sum of urea excretion and the daily change in the urea pool. No negative correlation was noted between urea appearance and urea degradation, as might be expected if portal ammonia were being utilized for protein synthesis. However, urea production was positively correlated (r = 0.76) with urea degradation, suggesting that most of the resulting portal ammonia is converted back to urea. The results fail to support the view that degradation of urea in the gut promotes N conservation in uremic subjects maintained on low protein diets.

Uptake of individual amino acids by perfused rat liver: effect of acute uremia.

ARTICLESUptake of individual amino acids by perfused rat liver: effect of acute uremiaWW LacyWW LacyPublished Online:01 Sep 1970https://doi.org/10.1152/ajplegacy.1970.219.3.649MoreSectionsPDF (1 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByHormonal status in critically ill patients with or without acute renal failureHepatic uptake and release of glucose, lactate, and amino acids in acutely uremic dogsMetabolism, Vol. 40, No. 3Contribution of the urea appearance rate to diuretic–induced azotemia in the ratKidney International, Vol. 32, No. 1Mechanism of hepatic assimilation of dipeptides. Transport versus hydrolysis.Journal of Biological Chemistry, Vol. 261, No. 32Enhanced Muscle Protein Degradation and Amino Acid Release from the Hemicorpus of Acutely Uremic RatsAmino acid release from the hindquarter and urea appearance in acute uremiaW. E. Mitch1 December 1981 | American Journal of Physiology-Endocrinology and Metabolism, Vol. 241, No. 6Studies on the role of the liver and splanchnic tissues in the production of carbohydrate intolerance in uremiaMetabolism, Vol. 30, No. 7Carbohydrate metabolism and uraemia ? Mechanisms for glycogenolysis and gluconeogenesisKlinische Wochenschrift, Vol. 58, No. 19Determinants of ureagenesis, with particular reference to renal failureKidney International, Vol. 17, No. 6LiteraturverzeichnisLiteraturverzeichnisPossible sites of interaction of acute renal failure with amino acid utilization for gluconeogenesis in isolated perfused rat liverEuropean Journal of Clinical Investigation, Vol. 7, No. 4Protein-catabolic state of isolated rat hepatocytesBiochimica et Biophysica Acta (BBA) - General Subjects, Vol. 496, No. 1Incorporation of radioactive amino acids into protein in isolated rat hepatocytesBiochimica et Biophysica Acta (BBA) - Nucleic Acids and Protein Synthesis, Vol. 442, No. 3Studies on Urea Cycle Enzymes in Rat Liver during Acute UraemiaEuropean Journal of Clinical Investigation, Vol. 5, No. 1Origin and Possible Significance of Alanine Production by Skeletal MuscleJournal of Biological Chemistry, Vol. 249, No. 23The Effect of Acute Uraemia on Gluconeogenesis in Isolated Perfused Rat Livers2 March 2011 | European Journal of Clinical Investigation, Vol. 4, No. 6The Effect of Acute Uraemia on Gluconeogenesis in Isolated Perfused Rat LiversEuropean Journal of Clinical Investigation, Vol. 4, No. 1Stimulierung der Glukoneogenese der isoliert perfundierten Rattenleber nach bilateraler NephrektomieÜber das Verhalten von Enzymaktivitäten des Harnstoffcyclus und über den Aminosäurestoffwechsel in der Leber bei akuter UrämieRegulation of the Transport and Metabolism of Amino Acids in Isolated Fat CellsJournal of Biological Chemistry, Vol. 245, No. 15 More from this issue > Volume 219Issue 3September 1970Pages 649-653 Copyright & PermissionsCopyright © 1970 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1970.219.3.649PubMed5450866History Published online 1 September 1970 Published in print 1 September 1970 Metrics