Effects of vitamin C on muscle glycogen and oxidative events in experimental diabetes

Streptozotocin (STZ) is an agent used in creating experimental diabetes. Varying findings have been reported about the striated muscle glycogen levels in diabetes. In this study, it was planned to observe interaction of vitamin C (AA), of which deficiency has been shown in diabetics, with soleus muscle glycogen levels and oxidative events on STZ-diabetic subjects.

In the study, 38 male adult Wistar Albino rats with weights 200 +/- 20 g were used by separating them into four groups: Control, Vitamin C, Diabetes, Diabetes + Vitamin C. Body weights and fasting blood glucose were measured at the beginning and end of the experiment. AA, TBARS, GSH, NOx and glycogen levels of soleus muscles, and AA level of blood were measured. The results were compared using Anova variance and Mann-Whitney U tests. Results showed that AA levels in blood increased with vitamin C administration; AA, GSH and NOx levels in the muscle were low and MDA and glycogen levels were high in diabetics; and that vitamin C in the given dosage partially corrected these values. These results indicate that higher dosage than daily 20 mg/kg Vitamin C is required for being effective on metabolic and oxidizing events in diabetic rats.