OBJECTIVETo investigate the biological characteristics of dermal fibroblasts of the diabetic rats with deep partial thickness scald, and to explore its relationship with delayed wound healing due to diabetes.

METHODSSprague-Dawley rats weighing 250 g were randomly divided into control (NM, n=40) and STZ-induced diabetic (DM, n=50) groups, and then deep partial thickness scald involving 10% TBSA were reproduced in the two groups. Skin samples were harvested from the wounds on 0, 3, 7, 14 and 21 post scald day (PSD) for the determination of certain histological characteristics.

RESULTSThe thickness of dermis layer in DM group before injury was obviously thinner than that in NM group (P < 0.01). There was an infiltration of a large amount of chronic inflammatory cells and increased content of cutaneous glucose in the dermal tissue in DM group (2.77 mg/g) compared with 0.85 mg/g in NM group, (P < 0.01). An accumulation of advanced glycation end products (AGEs) was found in the dermal tissue in DM group. After the scalding, the percentage of fibroblasts in S phase and hydroxyproline synthesis in DM group was evidently lower than those in NM group. But the apoptosis rate of fibroblasts was much higher in DM group than that in NM group (P < 0.05 or 0.01).

CONCLUSIONIt is found that the high contents of glucose and AGEs in diabetic skin exert untoward effects on biological characteristics of dermal fibroblast, probably constituting one of the underlying mechanisms of delay wound healing of scald in diabetic rats.