Abstract:

Objective To observe the histological changes of skin and explore its relationship with wound healing in diabetic nude mice. Methods Diabetic nude mice models were established by intraperitoneal injection of 150 mg/kg STZ. Full-thickness skin of 1.8 cm in diameter was obtained from the dorsum of normal control rats (n=20) and diabetic nude mice (n=20) 4 weeks after model establishment. HE staining was used to observe the histological changes of skin, and the thickness of dermis and epidermis was measured. Picrosirius red staining was employed to analyse the relative content of collagen in dermis. The cutaneous content of glucose was determined by glucose oxidase method. The wound closure rates were calculated 3 d, 5 d, 7 d, 14 d and 21 d after operation. Results The dermis and epidermis of diabetic nude mice were significantly thinner than those of normal controls (P<0.05), and the relative content of collagen in dermis of diabetic nude mice was significantly lower than that of normal controls (P<0.01). The concentration of blood glucose and cutaneous content of glucose of diabetic nude mice were significantly higher than those of normal controls (P<0.01), and there was a positive correlation between cutaneous content of glucose and concentration of blood glucose (r=0.951, P＜0.01). The wound closure rates of diabetic nude mice 3 d, 5 d, 7 d, 14 d and 21 d after operation were significantly lower than those in normal controls (P<0.01). Conclusion There are significant histological changes of skin in diabetic nude mice induced by STZ, and these changes may be related to the accumulation of advanced glycation end products, which may lead to the impaired wound healing.

Key words: streptozotocin, diabetic nude mice, skin, wound healing