ABSTRACT
First-pass metabolism (FPM) of orally ingested alcohol has been attributed to gastric alcohol dehydrogenase (ADH) activity in both humans and rats. To determine whether gastric alcohol dehydrogenase is essential for alcohol FPM, we sought a species lacking this enzyme. We found that Syrian golden hamsters have negligible gastric ADH yet alcohol FPM (265 +/- 25 mg ethanol/kg) was comparable to that of rats (251 +/- 31 mg/kg). To determine whether hamster gastric mucosal cells metabolize sufficient alcohol to account for this FPM, primary cultures were established, and these cells metabolized 1.99 +/- 0.84 mumol ethanol/10(6) cells/hr, an amount sufficient to account for the bulk of alcohol FPM. In contrast to alcohol dehydrogenase, catalase activity in hamster gastric mucosa (870 +/- 93 units/g tissue) was eightfold higher than in rat gastric mucosa (111 +/- 9 units/g tissue; P < 0.0001). FPM in hamsters treated with 3-aminotriazole was reduced from 242 +/- 24 to 130 +/- 22 mg/kg (P < 0.05) but was not reduced in rats. The results imply that catalase participates in gastric alcohol metabolism of hamsters.
