Slow contacting freezing method for deep wound in a rat model

Frostbite is a slow freezing injury, which was ignored by former animal model. We aim to create a frostbite wound animal model by slow contacting freezing method. Twenty four rats were brought into the study, with eight rats in each group. 2.5cm diameter copper billets(-25℃+1℃) were used to contact the rat dorsum for 30 minutes or 45 minutes, wound appearance, histology observation, wound healing rate, serum TXB2 and 6-keto-PGF1a levels were recorded. As a result, contacting for 45 minutes could lead to a full thickness damage of rats skin, and showed a significant difference in wound healing rate and serum TXB2 and 6-keto-PGF1a levels compared to the control group and 30 minutes group. In conclusion, we established a frostbite wound animal model by chronic hypothermia, which was more closed to the actual conditions. The model could fully display the pathological changes of the deep frostbite wound.冻伤是一种缓慢冻结性损伤，既往动物模型对该类损伤的研究存在一定忽视。本研究旨在通过缓慢接触冷冻法构建冻伤创面动物模型。本研究共纳入24只大鼠，分为3组，每组8只。采用直径2.5cm的铜坯（温度控制为-25℃±1℃）接触大鼠背部皮肤，接触时长分别为30分钟或45分钟，记录各组大鼠的创面外观、组织学观察结果、创面愈合率以及血清血栓素B2（TXB2）和6-酮-前列腺素F1α（6-keto-PGF1α）水平。结果显示，接触时长45分钟组可导致大鼠皮肤全层损伤，且该组的创面愈合率与血清TXB2、6-keto-PGF1α水平均与对照组及30分钟组存在显著差异。综上，本研究通过慢性低温接触法成功构建了冻伤创面动物模型，该模型更贴近临床冻伤的实际发病情况，可完整呈现深度冻伤创面的病理学变化。