Endogenous amino acid clearance by the rat kidney.

Abstract

SummaryAlthough studies on the clearance of endogenously circulating amino acids had been published for several mammalian and non‐mammalian vertebrate species, few data were available for the rat. Since micropuncture studies on the renal handling of amino acids are most conveniently performed on this species, endogenous clearance studies have now been undertaken using automated, ion‐exchange chromatographic techniques for amino acid analysis. Endogenous plasma amino acid concentrations were remarkably similar to those in man but renal clearances of most amino acids were considerably smaller, indicating highly efficient reabsorptive mechanisms; the urinary excretion patterns, also, were very similar to those of man, although a striking exception was observed in the case of taurine, which was cleared in the rat at rates approaching 40% of the glomerular filtration rate. It was concluded that the renal handling of amino acids, with the exception of taurine, was very similar in rat and man, so that conclusions drawn from micropuncture experiments in rats would seem likely to hold also for man.