Insulin delays platelet accumulation in injured cerebral microvessels of diabetic and normal mice

Pial arterioles of mice were injured by exposure to a noxious light/dye stimulus and resultant accumulation of platelets at the damaged site was monitored in vivo. When normal mice were injected with insulin 2 hr before damaging the arterioles, the accumulation of platelets was significantly delayed, but single injections of even higher doses failed to alter accumulation in mice with streptozotocin diabetes. When diabetic mice were placed on a schedule of daily injections of ultra lente insulin until normoglycemic, the treatment significantly delayed the accumulation of aggregating platelets in damaged vessels.