Diabetes mellitus is a metabolic disease associated with multiple organ damage, dysfunction and failure. Metformin
is widely used to treat diabetes, but regular exercise also improves metabolic control in diabetic individuals and
has an important role in the management of this disease. In this work, we compared the effects of metformin and physical
training in diabetic male Wistar rats. Four groups of rats were used: (n=6 per group): sedentary control (SC), sedentary
diabetic (SD), trained diabetic (DT) and metformin diabetic (MD). Diabetes was induced with alloxan (30 mg/kg, b.w.).
The physical training protocol consisted of a 1 h swimming session/day, five days/week for eight weeks with a load corresponding
to 5% of the body weight. Metformin treatment consisted in 1.4 mg/ml per day, administered in the drinking water.
At the end of the experimental period, the rats were sacrificed and blood was collected to measure serum glucose, insulin
and albumin. Glycogen was quantified in gastrocnemius muscle, liver and heart, the protein/DNA ratio was mensured
in liver and heart triglycerides was also measured in the heart. Diabetes reduced the serum insulin and liver glycogen
levels and the protein/DNA ratio, but increased the serum glucose and heart glycogen levels; there were no significant
variations in serum albumin levels. Physical training increased the muscle glycogen level. Physical training and metformin
were equally effective in reducing the serum glucose concentration and in restoring the hepatic and cardiac glycogen
stores and the hepatic protein/DNA ratio in diabetic rats. These results show that chronic exercise was as effective as
metformin in improving the metabolic profile of diabetic rats and in preventing diabetes-induced alterations.