EFFECT OF EBROTIDINE ON THE SYNTHESIS AND SECRETION OF GASTRIC SULFOMUCIN

1. The effect of a new antiulcer agent, ebrotidine, on the synthesis a nd secretion of sulfomucin in gastric mucosa was investigated. Rat gas tric mucosal segments were incubated in DMEM containing [H-3]proline, [H-3]glucosamine and ([S-35]Na2SO4)-S-35 as markers for mucin synthesi s, glycosylation and sulfation, in the presence of 0-150 muM ebrotidin e. 2. The drug, while showing no discernible effect on the apomucin sy nthesis, evoked a dose-dependent increase in mucin glycosylation and s ulfation, which at 100 muM ebrotidine, attained its maximum of 2.4 and 2.7-fold stimulation, respectively. 3. The analysis of mucin secretor y responses revealed that ebrotidine caused a concentration-dependent enhancement in sulfomucin secretion which attained its maximum increas e of 3.3-fold at 100-120 muM ebrotidine. Furthermore, the sulfomucin e laborated in the presence of ebrotidine exhibited a higher content of a large molecular-weight mucus glycoprotein form, the assembly of whic h is intimately associated with the sulfation event. 4. The results su ggest that the ability of ebrotidine to enhance gastric sulfomucin syn thesis and secretion may play an important role in the gastroprotectiv e mechanism of action of this agent.