OBSERVATIONS ON THE TREATMENT OF HUMAN GASTRIC AND COLONIC MUCUS WITH LYSOZYME 1

Abstract

Lysozyme from a human source (tears) and purified egg white lysozyme have been tested against various prepns. of human gastric and colonic mucus by the viscosimetric method of Meyer and Hahnel and by chemical analyses for the products of mucin digestion (mucoproteose). Neither whole gastric or colonic mucus from fistulous human subjects or its various prepns. at optimal pH values, nor any of the purified constituents of gastric mucus were measurably dissolved or digested by egg white lysozyme or human tear lysozyme. This was true not only of mucin obtained from aspirated fluids but also of the mucinous coating removed directly from the mucous membrane of the stomach and colon. Conversely, contact of lysozyme with gastric mucus did not impair the activity of the lysozyme on its mucinous bacterial substrate (Micrococcus lysodeikticus). In gastric mucus an autolytic process was noted at a neutral or slightly alkaline pH. Since this action was not affected by addition of either lysozyme or pepsin it seems likely that it is due to the presence of another mucolytic agent (enzyme ?) which acts at a neutral range of pH and which may be involved in the physiol. process of mucolysis in the human stomach under these conditions. These observations lead to the inference that whatever are the consequences of increased lysozyme secretion in ulcerative colitis, they do not include digestion of the protective layer of colonic mucus. Neither does lysozyme attack the protective mucus coating of the stomach, nor contribute to the formation of peptic ulcer by virtue of its dissolving or splitting action on the gastric mucus.