Effect of alloxan on insulin and glucagon secretion in perifused isolated islets

The effect of alloxan on insulin and glucagon secretion was investigated in perifused isolated rat islets. Five minutes of exposure to 1.4 mmol/l alloxan in a low-glucose medium (5.6 mmol/l) abolished subsequent leucine stimulated insulin and glucagon secretion. In a medium containing 19 mmol/l arginine and 3.3 mmol/l glucose, insulin secretion was only slightly diminished by alloxan pretreatment, whereas glucagon secretion was reduced to about 60% of controls. Exposure to alloxan in a high glucose medium (27.8 mmol/l) did not effect insulin or glucagon secretion.