Analysis of mucosal stress response in acid-induced esophagitis in opossum

This study is the first to examine site-specific changes in mucosal antioxidants and expression and localization of heat shock proteins (HSPs) following the induction of subacute esophagitis and after recovery using an established animal model. Distal, middle, and proximal samples were excised from anesthetized opossums 24 hr after three consecutive days of 45-min perfusion with saline or 100 mmol/liter HCI, or seven days after acid in recovery animals. Compared to controls, acid-induced erosive esophagitis significantly increased glutathione peroxidase and HSP90 at all sites and HSP60 proximally. Reduced glutathione was significantly decreased distally, as was HSP72 at distal and middle sites. No changes in superoxide dismutase or catalase occurred. After recovery, superoxide dismutase, catalase, and HSP expression were not different from controls. Glutathione peroxidase and glutathione were significantly decreased distally. Similar differential stress responses may occur in patients with chronic gastroesophageal reflux and could be important in the pathogenesis of reflux esophagitis.