INDUCTION OF CAPSAICIN-HYDROLYZING ENZYME-ACTIVITY IN RAT-LIVER BY CONTINUOUS ORAL-ADMINISTRATION OF CAPSAICIN

Effects of continuous oral administration of capsaicin (CAP) on the CAP-hydrolyzing enzyme activity in liver were investigated in rats. Rats were given a standard laboratory diet supplemented with 14 mg of CAP/100 g of diet, ad libitum, for 3 days and 1 and 3 weeks. It was found that CAP administration for 1 and 3 weeks significantly increased the CAP-hydrolyzing enzyme activity compared with that of each control group. Reaction products were chromatographically identified as vanillyl alcohol, vanillin, and vanillic acid. The CAP-hydrolyzing enzyme activity found in rat liver was also detected in chicken, hog, and bovine livers. It was suggested that the initial step of CAP metabolism was the hydrolysis reaction of the acid-amide bond in the CAP molecule and that this hydrolysis would be the rate-limiting step in CAP metabolism. These results suggest that the CAP-hydrolyzing enzyme activity reached maximum induction by continuous oral administration of CAP for 1 week.