Gamma-glutamyl transferase, intestinal alkaline phosphatase and beta-hexosaminidase activity in duodenal biopsies from chronic alcoholics.

OBJECTIVE

Gamma-glutamyl transferase (GGT) and intestinal alkaline phosphatase (IAP) are present in the brush border of mucosal absorptive cells in the small intestine. There are few studies on the effect of alcohol consumption on these enzymes. Increased intestinal GGT in biopsy specimens from the duodenum has been described in chronic alcoholics. In experimental animals alcohol effects varies with duration of exposure and with nutritional factors.

METHODS

IAP, GGT and the lysosomal enzyme beta-hexosaminidase (Hex) were examined in duodenal biopsy specimens from 23 defined chronic alcoholics and 33 non alcoholic controls. The results were correlated to serum GGT, alkaline phosphatase, CDT (Carbohydrate Deficient Transferrin) and the villus index.

RESULTS

Both the intestinal GGT (0.52 + 0.05 SEM vs. 0.30 + 0.024 SEM microkat/g protein, p<0.0001) and the IAP (22.11 + 2.49 SEM vs. 12.28 + 1.35 SEM microkat/g protein, p=0.0010) were significantly higher in alcoholics than in controls. There was no correlation between intestinal and serum alkaline phosphatase and GGT activity within the two groups.

CONCLUSIONS

Chronic alcohol consumption causes increased intestinal GGT and IAP activity in man. No effect on Hex was seen. The enzyme activity in the small intestine did not correlate to serum enzyme activity or to morphological changes in the small intestine.