Iron increases diabetes-induced kidney injury and oxidative stress in rats

Biol Trace Elem Res. 2014 Sep;160(3):368-75. doi: 10.1007/s12011-014-0021-9. Epub 2014 Jul 6.

Abstract

Diabetic nephropathy is both a common and a severe complication of diabetes mellitus. Iron is an essential trace element. However, excess iron is toxic, playing a role in the pathogenesis of diabetic nephropathy. The present study aimed to determine the extent of the interaction between iron and type 2 diabetes in the kidney. Male rats were randomly assigned into four groups: control, iron (300-mg/kg iron dextran), diabetes (a single dose of intraperitoneal streptozotocin), and iron + diabetes group. Iron supplementation resulted in a higher liver iron content, and diabetic rats showed higher serum glucose compared with control rats, which confirmed the model as iron overload and diabetic. It was found that iron + diabetes group showed a greater degree of kidney pathological changes, a remarkable reduction in body weight, and a significant increase in relative kidney weight and iron accumulation in rat kidneys compared with iron or diabetes group. Moreover, malondialdehyde values in the kidney were higher in iron + diabetes group than in iron or diabetes group, sulfhydryl concentration and glutathione peroxidase activity were decreased by the diabetes and iron + diabetes groups, and protein oxidation and nitration levels were higher in the kidney of iron + diabetes group as compared to iron or diabetes group. However, iron supplementation did not elevate the glucose level of a diabetic further. These results suggested that iron increased the diabetic renal injury probably through increased oxidative/nitrative stress and reduced antioxidant capacity instead of promoting a rise in blood sugar levels; iron might be a potential cofactor of diabetic nephropathy, and strict control of iron would be important under diabetic state.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Diabetes Mellitus, Experimental / metabolism*
  • Diabetes Mellitus, Experimental / pathology
  • Diabetic Retinopathy / metabolism*
  • Diabetic Retinopathy / pathology
  • Dietary Supplements / adverse effects*
  • Iron / toxicity*
  • Iron Overload / chemically induced
  • Iron Overload / metabolism
  • Iron Overload / pathology
  • Kidney / injuries
  • Kidney / metabolism
  • Kidney / pathology
  • Male
  • Oxidative Stress / drug effects*
  • Rats
  • Rats, Wistar

Substances

  • Iron