Absorption by the Mouse and Rat Urinary Bladder of Glycine, Tryptophan and Glucose

Abstract

THE passage of drugs, dyes and inorganic ions through the mammalian urinary bladder has been the subject of many investigations^1,2. However, few attempts have been made to ascertain if the mammalian bladder absorbs normally occurring, physiological components of urine, for example, amino-acids and sugars. It was observed³ during the course of investigations of the bladder carcinogenicity⁴ of certain urinary metabolites of the essential amino-acid, L-tryptophan, that nearly 90 per cent of the carbon-14 present in an aqueous solution of carbon-14-labelled 3-hydroxy-L-kynurenine or 3-hydroxyanthranilic acid, instilled directly into the mouse urinary bladder, was recovered after 24 h in the respiratory carbon dioxide, carcass, and faeces. These data suggested that other normally occurring urinary substances might also be absorbed by the bladder.