In Vitro Inhibition of Blood Cholinesterases by the Organophosphate Dichlorvos in Typ-2 Diabetic Patients

Abstract

Background: Cholinesterases may undergo metabolic alterations due to type 2-diabetes mellitus and their susceptibility to in vitro inhibition by organophosphate insecticides is not known. The aim of the study was to examine in vitro inhibition of plasma and erythrocyte cholinesterase activities in type-2 diabetic patients by the organophosphate insecticide dichlorvos. Methods: Plasma and erythrocyte cholinesterase activities were measured in 32 type-2 diabetic patients and 32 apparently healthy subjects by the spectrophotometric Ellman method. The 10-minute cholinesterase-inhibitor incubation method was used to examine the in-vitro inhibitory effects of dichlorvos (0.5 and 1 µM) on plasma and erythrocyte cholinesterase activities in type-2 diabetic patients vs. control healthy subjects. Results: Plasma and erythrocyte cholinesterase activities in type-2 diabetic patients were significantly higher than those of the apparently healthy control subjects. Dichlorvos at 0.5 and 1 µM in vitro significantly inhibited plasma and erythrocyte cholinesterase activities in both control and diabetic subjects. However, the percentages of blood cholinesterase inhibition in diabetic patients were more than those of respective control values. Conclusion:Patients with diabetes could be more sensitive to toxicity by cholinesterase inhibitors. Accordingly, caution should be practiced in patients using cholinesterase inhibitors.