RENAL EXCRETION OF L-TYROSINE AND ITS DERIVATIVES

¹ Department of Pharmacology, University of Louisville, School of Medicine, Louisville, Kentucky

Studies of the renal excretion of L-tyrosine and eight of its derivatives have shown that the mono-substituted derivatives behave similarly to L-tyrosine, namely they were reabsorbed by the renal tubules. In contrast, the disubstituted derivatives of L-tyrosine were secreted by the tubules. 3,5-Diiodo-L-tyrosine was used to represent the group of disubstituted compounds on the studies with stop flow technique. It was found that the secretion of this compound was localized in the proximal section and could be blocked by the administration of probenecid.