No sex and age influence on the expression pattern and activities of humangastric alcohol and aldehyde dehydrogenases

Background: Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) a re the principal enzymes responsible for ethanol metabolism in humans. The stomach is involved in the metabolism of alcohol during absorption. Conflic ting reports exist with regard to the influence of sex and age on the activ ity of ADH in the human gastric mucosa. The purpose of the present study wa s to determine the effects of age and sex on the expression pattern and act ivities of stomach ADH and ALDH. Methods: A total of 115 endoscopic gastric biopsy specimens were investigat ed from Han Chinese men (n = 70) and women (n = 45) aged 20-79 years with a pproximately even distribution among 10-year age intervals. The expression patterns of ADH and ALDH were identified by isoelectric focusing, and the a ctivities were assayed spectrophotometrically. Results: The expression patterns of gastric ADH and ALDH remained unchanged with respect to sex and age. At 33 mM or 500 mM ethanol, pH 7.5, the ADH a ctivities did not differ significantly among the Various age groups or betw een men and women. At 200 muM or 20 mM acetaldehyde, the ALDH activities di d not differ significantly in relation to sex and age. Na correlations were found between the ADH or ALDH activities at both the high and low substrat e concentrations and the ages in men and women. Conclusions: The results indicate that there is no significant effect of ei ther sex or age on the expression pattern and activity of ADH and ALDH in t he human gastric mucosa. The stomach ADH seems unlikely to account for poss ible variations in the first-pass metabolism of alcohol with regard to sex and age.