RENAL TUBULAR TRANSPORT AND MOLECULAR STRUCTURE IN THE ACETAMIDOBENZOIC ACIDS

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

The physical properties and behavior in the canine renal tubule have been examined for four acetamidobenzoic acids and some iodinated derivatives. Varying experimental conditions of urinary volume and acidity, and varying molecular weight, acidity, and lipoid solubility of the compounds lead to results indicating that the compounds undergo passive reabsorption from the lumen of the tubule in conformance with the classical theory of permeability. Ortho, meta, and para acetamidobenzoic acids are found to be well transported into the tubular lumen under conditions reducing their reabsorption. Flanking the acetamido group with iodine atoms does not reduce this transport, flanking the carboxyl group does so only slightly.