Antioxidant therapy and streptozotocin-induced diabetes in pregnant rats

The aim of our study was to analyse the effect of chronic hyperglycaemia on lipid peroxidation and scavenging enzyme activity in pregnant animals and their offspring supplemented and not supplemented with vitamin E - a natura l antioxidant. Thirty pregnant female Wistar rats were used in our experime nts. Diabetes was induced on day 7 of pregnancy using a single dose of stre ptozotocin (40 mg/kg). Diabetic animals were divided into two equal groups: vita min E supplemented and those fed with standard diet. Our controls con sisted of 15 healthy rats. On day 1 after delivery homogenates of maternal liver and uterus as well as neonatal lungs and liver were prepared. Then th e following parameters were measured: malondialdehyde (MDA) concentrations in the homogenates and blood serum, glutathione (GSH) levels, the activity of CuZn superoxide dismutase (SOD) and glutathione peroxidase (GPx) (Bioxyt ech, France). Statistical analysis was performed using Mann-Whitney U test. The neonates of diabetic rats were smaller than those from healthy rats an d serum glucose concentration was markedly higher in diabetic animals, both in mothers and neonates. MDA levels increased significantly, whereas GSH c ontent and SOD as well as GPx activities were markedly diminished in diabet ic pregnant rats and their offspring in comparison with the control group. In animals supplemented with tocopherol, MDA concentrations declined signif icantly, GSH contents and SOD activities were markedly elevated in almost a ll types of tissues studied, whereas glutathione peroxidase remained suppre ssed. Our results suggest that diabetic pregnant rats and their neonates ar e exposed to oxidative stress (OS), but vitamin E supplementation could in part reduce the imbalance between uncontrolled reactive oxygen species gene ration and scavenging enzyme activity, and may potentially serve as a usefu l prophylactic factor against OS development.