The bioelectrical properties of pancreatic islet cells: Effect of diabetogenic agents

Abstract

Alloxan 5 mM depolarised the islet but not the acinar cells of mouse pancreatic segments in vitro. This effect was prevented by D-glucose but not by glutathione, 3, 0, methyl-α-D-glucose, D-glucosamine, D-mannoheptulose, or L-leucine. Pretreatment of islet β-cells with streptozotocin 20 mM caused no depolarization but inhibited the generation of action potentials by D-glucose, L-leucine, D-mannose and D-glyceraldehyde, whereas tolbutamide-induced action potentials were not blocked; the alkylating moiety of streptozotocin, N-nitroso N- methyl urea produced similar effects. Prior exposure of the islet cells to nicotinamide 4.1 mM conferred protection against streptozotocin action. These observations are discussed in relation to the diabetogenic action of alloxan and streptozotocin. © 1972 Springer-Verlag.