[Involvement of sulfhydryls in the protective mechanism of gastric mucosa].

The present work have studied the role of nonproteinsulfhydryl (NPSH) in the protective mechanism of gastric mucosa. During the development of gastric injury induced by acidified ethanol (AE) gavage or restraint-cold stress (RCS), NPSH content in gastric mucosa markedly decreased. Pretreatment with cysteamine (cys) or reductive glutathione (GSH) could prevent gastric mucosa from injury induced by AE. The activity of glutathione reductase in gastric mucosa was inhibited consistently in the time course with NPSH decrease after AE gavage or RCS. Malondialdehyde (MDA) level in the mucosa increased after AE gavage and dimethyl suloxide, a free radical scavenger, could reduce AE induced injury. The above results suggest that NPSH in gastric mucosa might be involved in the local protective mechanism through its free radical scavenging activity, and the decrease of NPSH in gastric mucosa resulted by the inhibition of glutathione reductase activity and the increase of free radical production may be an important step in the development of injury.