EFFECT OF CHRONIC ETHANOL FEEDING ON INTESTINAL ALKALINE-PHOSPHATASE ACTIVITY IN RATS

The effect of chronic ethanol feeding has been studied on intestinal a lkaline phosphatase (IAP) activity. The enzyme mas assayed using p-nit rophenyl phosphate (PNPP), phenylphosphate (PhP) and beta-glycerophosp hate (beta GP) as the substrates. Feeding of ethanol for 10 days did n ot effect the enzyme activity but it mas markedly elevated in animals fed ethanol for 20 or 30 days. However, ethanol administration to rats , for over 6 wk exhibited a decline in IAP activity, both in the solub le and membrane fractions of intestine. Kinetic studies revealed an en hancement in Vmax with no change in apparent Km after 30 days of ethan ol feeding and a decrease in Vmax after 6 wk of ethanol ingestion. The se results were confirmed by assaying the enzyme activity in non-denat ured polyacrylamide gels using 5-bromo-4-chloro-3-indolyl phosphate (B CIP) as the substrate. These findings suggest differential changes in IAP activity in response to ethanol feeding in rats.