Acute and chronic effects of the organophosphate malathion on the pancreatic α and β cell viability, cell structure, and voltage-gated K plus currents.

Studies indicate that the pesticide malathion may have a role in diabetes. Herein, we determined the effects of different concentrations of malathion on survival, ultrastructure, and electrophysiologic islet cell parameters. Acutely, high concentrations of malathion (0.5 or 1 mM) increased cell death in rat islet cells, while low con-centrations (0.1 mM) caused signs of cell damage in pancreatic alpha and beta cells. Exposure of RINm5F cells to malathion for 24 or 48 h confirmed the reduction in beta-cell viability at lower concentrations (0.001-100 mu M). Chronic exposure of mouse pancreatic alpha and beta cells to 3 nM of malathion led to increased voltage-gated K+ (Kv) currents in alpha-cells. Our findings show a time and concentration dependency for the malathion effect on the reduction of islet cell viability and indicate that pancreatic alpha cells are more sensitive to malathion effects on Kv currents and cell death.

Automated summary

Studies have shown that the pesticide malathion may play a role in diabetes. This study investigated the effects of different concentrations of malathion on the viability, ultrastructure, and electrophysiological parameters of islet cells. High concentrations of malathion resulted in cell death in rat islet cells, while low concentrations caused damage to pancreatic alpha and beta cells. Chronic exposure to malathion increased voltage-gated K+ currents in alpha cells and reduced beta-cell viability.