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.