ABSTRACT
AIM: To clarify the effects of gastrin on t he expression of cyclooxygenase (COX) and several growth factors in rat gastric mu cosa. METHODS: Male Sprague Dawley rats were fasted for 24 hours and s ubcutaneously injected with saline or gastrin 17 at doses of 1 ?g/kg, 10 ?g/kg and 100 ?g/kg, respectively. The expression of COX-1, COX-2, heparin-binding e p idermal growth factor-like growth factor (HB-EGF) and hepatocyte growth factor ( HGF) in the gastric mucosa were examined using Western blotting and immunohistoc hemical staining. Effects of a potent gastrin receptor antagonist YM022 on the e xpression of COX-1, COX-2, HB-EGF and HGF in gastric mucosa were also evaluated. RESULTS: Gastrin dose-dependently increased the expression of C OX-2 and HB-EGF in rat gastric mucosa while the expression of COX-1 and HGF did not change significantly after treatment with gastrin. However, pretreatment wit h YM022 dose-dependently abolished the up-regulation of COX-2 and HB-EGF express ion induced by gastrin. CONCLUSIONS: This study demonstrates that gastrin up-regulates C OX-2 and HB-EGF expression in rat gastric mucosa, indicating that COX-2 and HB-E GF are involved in pathogenesis of the gastrin-related gastric mucosal hyperplas ia and carcinoma of stomach.