Distribution of polysaccharide components of human gastric juice in the electrophoretic partition

Abstract

A large pool of non-dialyzable solids of normal acid gastric juice was fractionated by paper electrophoresis. Over 350 electrophoretic strips were cut into 5 mm segments and after elution were analyzed for proteins, hexoses, hexosamine, fucose, sialic and uronic acids, and sulfates. The results obtained were correlated with mean electrophoretic patterns of the same gastric juice pool stained by amido black and PAS stains, traced, and analyzed by means of Gaussian curves. Three main protein peaks were found, which were localized in the areas corresponding to that of: (1) pepsin, (2) mucosubstances M2 and M3 (in which albumin is also located) and (3) X1 (where γ-globulin is present). Only one major carbohydrate peak was found, coinciding with that traced by electrophoresis and corresponding to the area of mucosubstance M3, which, on Gaussian curve analysis shows the presence of many components. The carbohydrate spectrum along the electrophoretic partition of the normal gastric juice also changes markedly, and points in the same direction. The anodic area contains highest concentration of sialic acid and hexoses and lower-most of hexosamine and fucose. The central area, which coincides with the carbohydrate peak, contains highest concentrations of hexosamine and fucose and is low in sialic acid. The cathodic area has highest concentration of hexoses, and lowermost of sialic acid, hexosamine and fucose. Sulfates form three peaks, of which the highest is located in the most anodic area, where no proteins and PAS-stainable carbohydrates are detected. The complexity of the distribution of sugars along the electrophoretic partition of the normal acid gastric juice suggests the presence of several carbohydrate materials and proteins of different composition. This indicates the inadequacy of any chemical analysis of the total non-fractionated acid gastric juice. The prevention of proteolysis by means of neutralization of gastric juice in vivo and in vitro simplifies the analytical problems but introduces an artifact which does not exist under physiological conditions in the normal stomach.