FIRST-PASS METABOLISM OF ETHANOL IS NEGLIGIBLE IN RAT GASTRIC-MUCOSA

Controversy exists concerning whether first-pass metabolism of imbibed ethanol occurs in the gastric mucosa or liver. We assessed ethanol me tabolism in rat gastric mucosa by determining to what extent intact [C -14]ethanol in body water plus hepatic metabolism could account for [C -14]ethanol absorbed from the pylorus-ligated stomach. Intact [C-14]et hanol in systemic body water accounted for 84 +/- 1.9% of the [C-14]et hanol absorbed from the stomach over a 30-min period, Assuming a 15 ml /min hepatic blood flow, the predicted hepatic metabolism of [C-14]eth anol over the 30 min of the study was 18% of the dose. The sum of inta ct [C-14]ethanol and predicted hepatic metabolism accounted for 100% o f the ethanol absorbed from the stomach. We conclude that negligible m etabolism of ethanol occurred in the gastric mucosa.