Objective   To investigate the effects of rosiglitazone on serum levels of tumor necrosis factor-α (TNF-α)

interleukin-6 (IL-6)

C-reactive protein (C-RP) and superoxide dismutase (SOD)

and early skin changes in the diabetic rats.    Methods   The rats were divided into normal control group (C group

n=13)

diabetic control group (DC group

n=13)

diabetes and insulin treatment group (DI group

n=13)

diabetes and rosiglitazone treatment group (DR group

n=13). The diabetic rat models were established with high-fat diet for 2 weeks followed by intraperitoneal injection of 35 mg/kg streptozotocin injection

the rats were idenfied as diabetic when their fasting blood glucose (FBG) over 7.0 mmol/L. The living rats were given corresponding treatment

subcutaneous injection of 1 to 2 U/d insulin

intragastric injection of 5 mg/(kg·d) rosiglitazone

or sterile water. Heart blood samples of rats from each group were collected to measure TNF-α

IL-6

C-RP and SOD levels in the 16th weekend. Also the skin was taken for pathological observation and fullthickness as well as dermal thickness measurements.    Results   The serum levels of IL-6

TNF-α and C-RP in diabetic group were significantly higher than those in normal group (P0.05)

and no difference was found in DI group and DR group compared with the normal control group. The SOD level of diabetic group was significantly lower than normal control group (P0.01)

and the SOD levels of insulin and rosiglitazone group were significantly increased compared with the diabetic group (P0.01). Micrometer measurements showed that the skin of diabetic rat was significantly thinner than that of the normal

insulin and rosiglitazone treatment groups after 16 weeks (P0.01

0.05). The epidermal cell layers were not clear enough

and dermal layer collagen atrophy

degeneration

and progressive subcutaneous fat atrophy were found by histology observation. No obvious histological change were seen in DI and DR groups.    Conclusion   Both rosiglitazone and insulin can reduce serum inflammatory mediators

increase SOD levels in diabetic rats

and exert a protective effect on early skin lesions.