Subacute Effects of Carbofuran on Enzyme Functions in Rat Small Intestine

Abstract

The effect of carbofuran administration to rats has been studied on enzymes functions in rat intestine. Carbofuran was administrated 4.0 mg/kg body weight for 7 days or 2.8 mg/kg body weight for 30 days daily by Ryle's tube. Animals given carbofuran for 30 days exhibited retarded growth compared to control group. The activities of sucrase (56%), alkaline phosphatase (62%), leucine aminopeptidase (56%), and γ-glutamyl trans peptidase (84%) were enhanced in animals given carbofuran for 7 days. Enhancement in the activities of alkaline phosphatase and leucine amino peptidase (92–96%) was also observed in animals exposed to carbofuran for 30 days, but the activities of sucrase (28%) and γ-glutamyl transpeptidase (49%) were reduced under these conditions. There was no change in activities of maltase, lactase, and trehalase in pesticide-treated animals for 7 or 30 days. The activity of lactate dehydrogenase was enhanced (p < 0.001) in 7 days and 30 days induced carbofuran toxicity. The activities of glucose-6-phosphatase and glutamate pyruvate transaminase were also enhanced (p < 0.001) in pesticide-treated animals for 7 days, but were reduced by 46% and 26%, respectively, after 30 days of carbofuran exposure. The activity of glutamate oxaloacetate transaminase was unaltered in carbofuran toxicity. Kinetic analysis of brush border enzymes revealed a change in V_max with no change in apparent Km. Western blot analysis of brush border sucrase, alkaline phosphatase, and leucine aminopeptidase corroborated the enzyme activity data. Intestinal histological revealed distruption of the villi, and comet assay showed disintegration of DNA in enterocytes of animals exposed to carbofuran for 30 days. These findings suggest that carbofuran toxicity may modulate digestive functions in rat intestine.

KEYWORDS:

• Carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl N-methyl carbamate)
• Brush Border Enzymes
• Cellular Enzymes
• Intestinal Morphology

Nidhi Gera was supported by Research Fellowship provided by University Grants Commission, New Delhi.