Adenosine triphosphatase activity of streptozotocin-induced diabetic rat brain microsomes. Effect of vitamin E.


Das Evcimen N., Ulusu N., Karasu Ç. , Dogru B.

General physiology and biophysics, vol.23, no.3, pp.347-55, 2004 (Journal Indexed in SCI Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 23 Issue: 3
  • Publication Date: 2004
  • Title of Journal : General physiology and biophysics
  • Page Numbers: pp.347-55
  • Keywords: diabetes, calcium, ATPase, vitamin E, brain, LIPID-PEROXIDATION, EXPERIMENTAL GALACTOSEMIA, ANTIOXIDANT THERAPY, RETINAL METABOLISM, COMPLICATIONS, ABNORMALITIES, PHOSPHOLIPIDS, GLYCOSYLATION, PRODUCTS, MEMBRANE

Abstract

Hyperglycemia causes protein glycosylation, oxidation and alterations in enzyme activities, which are the underlying causes of diabetic complications. This study was undertaken to test the role of vitamin E treatment on Ca2+-ATPase activity; protein glycosylation and lipid peroxidation in the brain of streptozotocin (STZ)-induced diabetic rats. Male rats weighing about 250-300 g were rendered diabetic by a single STZ injection of 50 mg/kg via the tail vein. Both the diabetic and non-diabetic rats were fed a vitamin E supplemented diet (500 IU/kg/day). Ca2+-ATPase activity was significantly reduced at week 10 of diabetes compared to the control group (p < 0.05), with 0.225 +/- 0.021 U/l (mean +/- S.E.M.) in the control group and 0.072 +/- 0.008 U/l (mean +/- S.E.M.) in the diabetic group. Vitamin E treatment prevented the enzyme activity from decreasing. The activities observed were 0.226 +/- 0.020 U/l and 0.172 +/- 0.011 U/l (mean +/- S.E.M.) in the vitamin E-treated control and diabetic group, respectively. STZ-induced diabetes resulted in an increased protein glycosylation and lipid peroxidation. Vitamin E treatment led to a significant inhibition in blood glucose, protein glycosylation and lipid peroxidation, which in turn prevented abnormal activity of the enzyme in the brain. This study indicates that vitamin E supplementation may reduce complications of diabetes in the brain.