The Effect of Chlorpyrifos, an Organophosphorus Pesticide, on Glucose Uptake in Whole Blood

Abstract

Background: The sub-chronic organophosphorous pesticide exposure increases insulin resistance and thereby the risk of developing Diabetes mellitus. Its acute exposure also leads to hyperglycemia. However, the mechanism is not clearly understood. Hence the present study explores the effect of low and high concentrations of chlorpyrifos, an organophosphorous pesticide on glucose uptake by whole blood and its possible mechanism. Methods: Level of hemolysis was determined at 2 and 4 hours of 1% DMSO (Dimethyl sulfoxide) and chlorpyrifos (0.3 and 10 mg/ml) exposure. The whole blood was treated in vitro with vehicle i.e., 1% DMSO or high (10 mg/mL) or low (0.3 mg/mL) concentrations of chlorpyrifos dissolved in DMSO. Then plasma glucose was assayed by glucose oxidase method at 2 and 4 hours of DMSO/chlorpyrifos exposures. Results: There was no effect of DMSO or 0.3 mg/ml chlorpyrifos treatment on hemolysis even after 4 hours. 10 mg/ml chlorpyrifos causes 2% and 14% hemolysis at 2 and 4 hours respectively. Plasma glucose level decreased in a time dependent manner after collection of blood (15.9% at 2 hours and 34.2% at 4 hour) in presence of DMSO. Chlorpyrifos did not influence glucose uptake by whole blood in low concentration but suppressed it in high concentration. Conclusion: Chlorpyrifos does not impair glucose uptake at low concentration in whole blood probably because major glucose uptake in blood is insulin independent. The impaired glucose uptake at high concentration is mostly due to toxic metabolic impairment and partly due to its hemolytic effect.