Oral administration of potassium dichromate inhibits brush border membrane enzymes and alters anti-oxidant status of rat intestine.

Potassium dichromate (K2Cr2O7) is a soluble hexavalent chromium compound that is widely used in several industries. In the present work the effect of administration of K2Cr2O7 on rat intestinal brush border membrane(BBM) enzymes and anti-oxidant system was studied. Rats were given a single oral dose of K2Cr2O7 (100 mg/kg bodyweight) and sacrificed 6, 12, 24, 48 and 96 h after the treatment.Control animals were not given K2Cr2O7. The administration of K2Cr2O7 resulted in a reversible decline in the specific activities of several BBM enzymes. The decrease in the activities of these enzymes was due to changes in the maximum velocity while their affinities for the substrates remained unchanged. Lipid peroxidation increased while total SH groups decreased in K2Cr2O7-treated rats as compared to controls indicating increased oxidative stress in the intestinal mucosa. The activities of superoxide dismutase and glutathione-S-transferase increased while those of catalase, glutathione reductase, thioredoxin reductase and glucose-6-phosphate dehydrogenase decreased. The maximum changes in all the parameters studied above were 24 h after administration of K2Cr2O7 after which recovery took place,in most cases almost to control values after 96 h. These results show that oral administration of K2Cr2O7 to decrease in the activities of BBM enzymes, increase in oxidative stress and alters the activities of anti-oxidant enzymes in rat intestine.