Renal Excretion of Phlorizin and Phlorizin Glucuronide

Abstract

A study was made of the excretion of the glycoside, phlorizin, in the dog using the phenol method of Folin and Ciocaltieu combined with separation of phlorizin from other phenols by filter paper chromatography. Phlorizin was found to be filtered through the glomeruli and secreted by the tubules. The phenomenon of tubular secretion of phlorizin was also observed in the domestic chicken and the aglomerular fish, Lophius americanus. In the dog the tubular secretion of phlorizin is inhibited by Benemid and p-aminohippurate. The glucuronide of phlorizin was found in plasma and urine of the dog and urine of the chicken during phlorizin infusion. It is excreted predominantly by glomerular filtration in the dog during phlorizin administration. Benemid, while blocking tubular secretion of phlorizin, uncovers a tubular secretion of the glucuronide. The interrelations between phlorizin and phlorizin glucuronide in tubular secretion are discussed as well as the relation of the transport of these same two substances to the phlorizin block of secretion of phenol red, Diodrast and p-aminohippurate and the reabsorptive inhibition of glucose.