The role of gastric mucosal sulphydryls in the ulcer-protecting effects of cisapride

Abstract

The present study was designed to examine the role of endogenous sulphydryls (SHs) in the gastroprotection induced by cisapride (CIS) (10, 25 and 50 mg kg-1 i.p.), a potent benzamide stimulating gastrointestinal motility in mucosal injury induced by 50% v/v ethanol. Results were compared with those of 5-hydroxytryptamine (5-HT) (10 mg kg-1). Ethanol mucosal damage was significantly reduced by treatment with CIS and 5-HT. On the contrary, administration of n-ethylmaleimide (NEM) (10 mg kg-1) an SH alkylator, markedly worsened lesion formation and counteracted the protective effect of CIS. Rats pretreated with CIS significantly increased the total sulphydryls as reflected in the non-protein and protein fractions however, 5-HT treatment showed a fall in the non-protein level. The present results suggest that 5-HT-ergic dependent mechanisms have no relation to the gastroprotection afforded by CIS in this experimental model. It is possible that mucosal SHs could be involved.