动物造模 z-bio 2022-09-05 455

　　Objective To construct a rat model of chronic skin ulcer by different methods, and to evaluate the differences and respective characteristics of different models through a variety of indicators.

　　Methods Rats were randomly divided into 4 groups, and different factors were applied on the basis of establishing open wounds with full-thickness skin defects: skin defect group (skin lesion group), skin defect + hormone interference group (skin lesion + hormone group) , skin defect + hormone interference + bacterial infection group (skin lesion + hormone + bacteria group), skin defect + foreign body group (skin lesion + foreign body group); during the experiment, the body weight of the rats was measured, and their activity status and wound healing were observed. The samples were collected on the 14th day, and the local pathological morphology of the ulcer tissue was observed, and the index of immune organs, blood leukocyte level, hydroxyproline (Hyp), total protein and tumor necrosis factor-a (TNF-a) in granulation tissue were detected. content.

　　Results During the experiment, there was no significant difference in the body weight of the rats in each group. After modeling, the wounds of the rats in the skin lesion group healed faster, while the "difficult-to-heal" phenomenon in the skin lesion + hormone group lasted for a relatively short time. The color of granulation was gray and white, but the growth rate of granulation was faster in the later stage, while the wounds in the skin lesion + hormone + bacteria group had the characteristics of yellow pus and the growth rate of granulation tissue was slow; pathological observation showed that the skin lesions + hormone + bacteria group, skin lesions The infiltration of inflammatory cells in the + foreign body group was significantly higher than that in the skin lesion group. The other three model groups showed an increase in the spleen index, an increase in the level of white blood cells, and a significant decrease in the hydroxyproline content in the wound tissue (P<0.05 or P<0.01). In the skin lesions + hormone + bacteria group, the total protein content was significantly decreased (P<0.05), and the TNF-α content was significantly increased (P<0.05).

　　Conclusion After adding different intervention factors on the basis of full-thickness skin excision, the healing speed of skin ulcers in rats is slowed down to varying degrees. Among them, the skin lesions + hormones + bacteria model has stable pathological characteristics and long duration, which can be used as a chronic refractory disease. The preferred models of skin ulcers, skin lesions + hormones, skin lesions + foreign body models, may be more suitable for short-term refractory wound research, and the latter can also be used to observe the simple granulation growth in the early stage of the wound.