THE INFLUENCE OF GLUCOSE RENAL TUBULAR REABSORPTION AND P-AMINOHIPPURIC ACID TUBULAR EXCRETION ON THE SIMULTANEOUS CLEARANCE OF ASCORBIC ACID

Abstract

When p-aminohippuric acid is excreted at a maximal rate by the renal tubules of the dog, the simultaneous tubular reabsorption of ascorbic acid is temporarily blocked. Reabsorption begins again but does not recover its original rate during 50 mins. of observation. Similarly, when glucose is being reabsorbed at a maximal rate, ascorbic acid reabsorption is at first blocked and in the same manner undergoes partial recovery. Although their respective tubular mechanisms do not interfere, glucose and p-aminohippuric acid when simultaneously infused depress ascorbic acid reabsorption to a greater degree than does each substance singly. This indicates that the observed interference could not have resulted from competition for a specific transport mechanism. Because of the non-specific nature of the competition, the view is favored that the observed interrelationship is in the system which supplies energy for tubular transfer.