Abstract
Amino acids are reabsorbed in the proximal convoluted tubules of the kidney. Their reabsorption is said to be essentially complete in the fasting state when speaking of endogenous amino acids; but when the amounts of amino acids filtered by the renal corpuscle are increased, both the amounts excreted and the amounts reabsorbed are also increased. The mechanism for reabsorption of the amino acids is different from that of glucose. | It has been shown by Beyer et. al. (1947) and others that the reabsorption of some amino acids is almost complete and that the reabsorption of others shows a well-defined transport maximum or Tm. Further, the infusion of large amounts of two given amino acids show, upon analysis of the urine produced, that there may be a competition for reabsorption between two amino acids A and B but not between amino acids C and D or A and C, etc. For example, Beyer et. al. (1947) found a competition between the pairs arginine and lysine and leucine and isoleucine, but no competition between arginine and glycine or leucine and glycine. | The matter is complicated by the finding that the infusion of a mixture of amino acids affects the reabsorption of other endogenous amino acids depending on the amount and composition of the amino acid mixture being infused.