Expression of Cytochrome P450 3A4 in Foveolar Epithelium with Intestinal Metaplasia of the Human Stomach

The expression of cytochrome P450 3A4 (CYP3A4) in the foveolar epithelium of the human stomach with intestinal metaplasia was studied using immunohistochemistry, western blotting and reverse transcription polymerase chain reaction (RT‐PCR). CYP3A4 was immunohistochemically detected in the foveolar epithelium with intestinal metaplasia, but was not detected in foveolar epithelium without intestinal metaplasia, in the pyloric gland or in the fundic gland of the stomach. Western blotting and RT‐PCR demonstrated that CYP3A4 protein and mRNA were expressed in the liver and pyloric gland mucosa with intestinal metaplasia, but not in the fundic gland mucosa without intestinal metaplasia. Possible roles of CYP expression in the gastric mucosa with intestinal metaplasia in human stomach carcinogenesis are briefly discussed.