Changes in gastric mucosal ornithine decarboxylase and tyrosine phosphorylation of proteins in postgastrectomy patients.

Abstract

There is evidence to suggest that partial gastrectomy is associated with an increased risk of developing gastric carcinoma in humans. Since ornithine decarboxylase (ODC) and tyrosine phosphorylation of proteins are involved in the regulation of cell proliferation, the present study was undertaken to examine the time-dependent changes of these variables in the postgastrectomy stomach. Thirty-seven postgastrectomy patients (Billroth I (BI), n = 7, and Billroth II (BII), n = 30) underwent gastroscopy. For comparison, five patients with intact stomachs (three healthy and two postvagotomy and pyloroplasty) were also studied. Gastric mucosal biopsy specimens were obtained within 5 cm of the anastomosis and analyzed for ODC activity. In addition, tyrosine phosphorylation of membrane proteins was also determined in representative samples of BII patients. Gastric mucosal ODC activity was significantly higher in BII patients in whom gastrectomy had been performed > 15 years earlier compared with those in whom it had been performed < 15 years earlier (p < 0.001) or controls (p = 0.004). Although the mean ODC activity was higher in BII than in BI patients, the difference was not significant (p = 0.103). Isolated patients with high ODC activity demonstrated increased phosphorylation of tyrosine membrane proteins with M(r) of 55-60.