Dl-Buthionine- S, R-sulfoximine affects intestinal alkaline phosphatase activity

Abstract

The susceptibility of intestinal alkaline phosphatase to dl-buthionine- S, R-sulfoximine was investigated in chicks fed a commercial diet. The results show that dl-buthionine- S, R-sulfoximine produced inhibition of intestinal alkaline phosphatase activity. This effect showed dose- and time-dependency and it was caused by either in vivo dl-buthionine- S, R- sulfoximine administration or in vitro dl-buthionine- S, R-sulfoximine incubation with villus tip enterocytes. dl-Buthionine- S, R-sulfoximine did not act directly on intestinal alkaline phosphatase but it provoked glutathione depletion which led to changes in the redox state of the enterocyte as shown by the production of free hydroxyl radicals and an incremental increase in the carbonyl content of proteins. The reversibility of the buthionine sulfoximine effect on intestinal alkaline phosphatase was proved by addition of glutathione monoester to the duodenal loop.