Lipid peroxidation in early experimental diabetes in rats: effects of diabetes and insulin

The degree of lipid peroxidation was measured in organs from diabetic rats receiving no treatment, and in those from insulin-treated diabetic rats and controls. Lipid peroxidation was measured as organ content of malondialdehyde, a degradation product of polyunsaturated fatty acids. In the kidney, lipid peroxidation was increased after one week of diabetes; insulin treatment reduced the level of lipid peroxidation to levels lower than seen in controls. In the liver, diabetes caused an increased lipid peroxidation, which could be reversed by insulin; no additional effect of insulin was found. In heart and pancreas no effects of diabetes or insulin were demonstrated. The present paper provides evidence that lipid peroxidation is increased in the early stages of experimental diabetes and is reversible by insulin treatment. Hyperinsulinaemia may, in itself, counteract lipid peroxidation in kidney.