Histamine and chondroitin sulfate E proteoglycan released by cultured human colonic mucosa: indication for possible presence of E mast cells

An association between the release of histamine and chondroitin sulfate E proteoglycan (PG) was demonstrates in human colonic mucosa (HCM). Colonic biopsy samples incorporated [35S]sulfate into PG, which was partially released into the culture medium during the incubation period. Ascending thin-layer chromatography of the released 35S-labeled PG after its digestion by chondroitin ABC lyase (chondroitinase, EC 4.2.2.4) followed by autoradiography yielded three products that migrated in the position of monosulfated disaccharides of N-acetylgalactosamine 4-sulfate and N-acetylgalactosoamine 6-sulfate and of an oversulfated disaccharide possessing N-acetylgalatosamine 4,6-disulfate. Cultured colonic mucosa released 23.6 +/- 3.7ng of histamine per mg of wet tissue without any special trigger. Comparison by linear regression analysis of the release of histamine and chondroitin [35S]sulfate E PG revealed a correlation coefficient (r) of 0.7. Histological examination of the colonic biopsies revealed the presence of many mast cells in various degrees of degranulation in the mucosa and submucosa. The above correlation, the observation that most of the mast cells showed various degrees of degranulation, and the lack of heparin synthesis as opposed to the synthesis and immunological release of chondroitin sulfate E strongly suggest that the E mast cell exists in the human colon