ORIGINAL

A study on the production of a reactive oxygen by leukocytes of diabetic rats

Abstract

To clarify the mechanism of decrease in the bactericidal activity of leukocytes in diabetes, rats with streptozotocin (STZ) diabetes were prepared for examination of the production of supero xide anion (O₂^-), a reactive oxygen produced by leukocytes, and the effect of insulin on this production. O ₂^- production was measured in microtiter plate wells by the cytochrome c reduction method. Opsonized zymosan, phorbol myristate acetate and Ca ionophore A 23187 were used as stimulants. The diabetic group showed a significantly higher blood glucose level, lower blood insulin level and lower O ₂^- production by macrophages with all three stimulants than those of the normal group. The amount of O₂^- produced by macrophages in the STZ-insulin group was slightly higher than that in the diabetic group. The diabetic, STZ-insulin and normal groups showed no significant difference in superoxide dismutase activity. There were significant correlations between the respective O₂^- production in re-sponse to the stimulants and the blood glucose level or the blood insulin level (p<0.01), respectively.These findings suggest that a decrease in O₂^-production in leukocytes is one of the causes of the decrease in the bactericidal activity in diabetes.