We investigated the role of ascorbic acid on the redox status in streptozotocin-induced diabetic
rats. In the plasma of diabetic rats, the ratio of reduced/total ascorbic acid was significantly
decreased as compared with normal control. Ascorbic acid ...
We investigated the role of ascorbic acid on the redox status in streptozotocin-induced diabetic
rats. In the plasma of diabetic rats, the ratio of reduced/total ascorbic acid was significantly
decreased as compared with normal control. Ascorbic acid supplementation increased
the reduced and total ascorbic acid contents as compared with diabetic control. In the rutintreatment
group, reduced and total contents of ascorbic acid were significantly decreased,
however, the ratio of reduced/total contents of ascorbic acid had no difference as compared
with diabetic rats. In the insulin-treatment group, this ratio is not significantly different as compared
with diabetic control. However, in the insulin plus ascorbic acid treatment group, reduced
form and the ratio of reduced/total ascorbic acid were significantly increased as compared with
diabetic control. In addition, we measured the contents of malondialdehyde (MDA) in the
plasma of diabetic rats. The contents of MDA was increased as compared with normal control,
however, in insulin-treatment group, the contents of MDA was decreased as compared with
diabetic rats. Ascorbic acid had no effects on the increases of MDA in diabetic rats. In conclusion,
plasma ascorbic acid level and its reduced/total ratio reflects the status of the oxidative
stress in the diabetic rats. Supplement of ascorbic acid did not correct the ratio of the reduced/
total ascorbic acid. However, supplement of insulin and ascorbic acid corrected the ratio of
reduced/total ascorbic acid.