[Effects of aerobic exercise combined with melatonin on osteoporosis of type II diabetic rats]

To investigate the effects of aerobic exercise and melatonin on osteoporosis in type 2 diabetic rats.

Sixty fe male SD rats were randomly divided into the control group (n=10) and the diabetic model group (n=50). The rats in the control group(N group) did not receive any intervention, and the rats in the type Ⅱ diabetic group (D) was injected with streptozocin(STZ) at the dose of 35 mg/kg by intraperitoneally. One week later, rats with blood glucose greater than 16.7 mmol/L were successfully modeled for type Ⅱ diabetes. Forty diabetic rats were randomly divided into diabetic control group (D), diabetes + aerobic exercise group(CDE),diabetes + melatonin group (DM), diabetes mellitus + aerobic exercise + melatonin group (DEM), 10 rats in each group. The rats in DE and DEM groups were treated with 20 min aerobic exercise for 6 weeks. The rats in DM group and DEM group were given 40 mg/kg of melatonin per day. The body weight, vertebrae and left and right femur bone mineral density (BMD) of the rats in each group were observed. Malondialdehyde(MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), serum total calcium (Ca), inorganic phosphate (P) and parathyroid hormone (PTH) were detected.

Compared with N group, body weight, serum SOD, GSH-Px levels, blood Ca, lumbar and femoral BMD of rats in group D were decreased significantly (P < 0.05 or P < 0.01). The levels of blood glucose, serum MDA and serum PTH were increased sig-nificantly (P < 0.01), the level of blood P had no changes (P > 0.05); compared with group D, DE group, DM group rats body weight, serum SOD, GSH-Px levels, blood Ca, lumbar spine and femur about BMD were increased significantly (P < 0.05 or P < 0.01). The levels of blood glucose, serum MDA and serum PTH were decreased significantly (P < 0.05 or P < 0.01), the level of blood P had no changes (P > 0.05). The effects in diabetic rats treated with aerobic exercise and melatonin at the same time were much better.

Both aero-bic exercise and melatonin can improve diabetic osteoporosis, and the effect of both joint intervention is more significant, it may be associated with oxidative stress by increasing the ability of diabetic rats, regulate glucose metabolism in order to effectively reduce the calcium and PTH, improve BMD to alleviate osteoporosis.