Increased production of transforming growth factor α following acute gastric injury

Abstract

Transforming growth factor a (TGF-α) production recently has been found in normal mammalian gastric mucosa. Inasmuch as TGF-α and epidermal growth factor (EGF) both stimulate epithelial cell migration and proliferation and suppress gastric acid secretion, the authors of the current study proposed that these growth factors may participate in tissue repair after acute gastric mucosal injury. Consequently, TGF-α and EGF production were examined after orogastric administration of either acidified taurocholate or 0.6 mol/L HCl to rats. TGF-α messenger RNA (mRNA) expression increased in a dose- and time-dependent manner after administration of taurocholate, whereas EGF mRNA expression was not detected. Radioimmunoassay of gastric mucosal scrapings obtained 6 hours after gastric injury induced by 0.6 mol/L HCl showed a 2.1-fold increase in immunoreactive TGF-α but no increase in immunoreactive EGF. In addition, there was a 68-fold increase in immunoreactive TGF-α in gastric juice within 30 minutes of gastric instillation of HCl and, again, no increase in immunoreactive EGF. There is a rapid appearance of TGF-α in the gastric juice within 30 minutes of injury, which is followed by increased expression of TGF-α mRNA and protein in the gastric mucosa. These studies suggest that locally produced TGF-α may participate in gastric mucosal repair following acute gastric injury to rats.