通过低温乙醇浸泡法制备冻伤动物模型，制备丹红复温液，研究其对冻伤大鼠早期组织微循环的影响。

将30只Wistar大鼠在-20 ℃制成冻伤模型，按照抛硬币法随机分成实验组和对照组，每组各15只。实验组采用丹红复温液，配比为1 000 mL 0.9%氯化钠注射液加入丹红注射液200 mL，恒温42 ℃；对照组采用常规复温液，0.9%氯化钠溶液1 000 mL，恒温42 ℃；各组复温时间为30 min/次，3次/d。分别于冻伤复温后24、48、72 h切取部分冻伤组织，制成5 mm×5 mm的病理切片，进行苏木精-伊红染色和免疫组织化学染色，通过荧光显微镜观察2组大鼠在冻伤复温后不同时相点冻伤组织的病理形态学特征及血管内皮的完整性情况；同时于上述观察点取大鼠眶内血液，检测循环血液中内皮细胞的数量。数据行配对t检验、重复测量方差分析。

冻伤复温后24 h，可见实验组和对照组均出现表皮萎缩，角质层减少的现象，实验组可见皮肤附属器，对照组无皮肤附属器；冻伤复温后48 h，2组均发生真皮变性，实验组真皮完整，对照组组真皮缺损，不连续；冻伤复温后72 h，可见实验组血管内皮细胞细胞核的数量明显多于对照组。实验组冻伤复温后24、48、72 h的内皮细胞计数分别为(3.05±0.27)×10⁷/L、(4.29±0.31)×10⁷/L、(5.14±0.21)×10⁷/L；对照组的内皮细胞计数分别为(3.62±0.14)×10⁷/L、(4.87±0.69)×10⁷/L、(5.90±0.56)×10⁷/L，随着复温时间的增加，2组内皮细胞数量呈逐渐递增趋势，差异均有统计学意义(F＝72.49、233.30，P<0.05)；不同时相点，实验组与对照组组间比较，差异均有统计学意义(t＝7.26、2.97、4.92，P<0.05)。

通过模拟大鼠冻伤模型，给予早期复温治疗，发现丹红复温液可降低血管内皮细胞的受损率，减少冻伤组织微循环的损伤，由此可见丹红复温液可用于早期冻伤治疗，而且其疗效优于常规复温液。

To prepare frostbite animal model by low-temperature ethanol immersion method, prepare Danhong rewarming solution, and study its effect on early tissue microcirculation in rats with frostibite rat model.

Thirty Wistar rats were made into frostbite model at -20 ℃ and randomly divided into experimental group and control group according to coin tossing method, 15 rats in each group. The experimental group was treated with Danhong rewarming solution in the ratio of 1 000 mL of 0.9% sodium chloride injection and 200 mL of Danhong injection at a constant temperature of 42 ℃. The control group was treated with routine rewarming solution, with 0.9% sodium chloride solution 1 000 mL, constant temperature 42 ℃. Each group was rewarming for 30 minutes/time, 3 times/d. Some frostbitten tissues were cut at 24, 48 and 72 hours after rewarming to make 5 mm × 5 mm pathological section. The pathomorphological characteristics and vascular endothelial integrity of frostbite tissue were observed by fluorescence microscope under hematoxylin-eosin staining and immunohistochemical staining at different time points of frostbite rewarming, and the number of endothelial cells in circulating blood was detected.Data were processed with paired t test and repeated measures analysis of variance.

At 24 hours after frostbite rewarming, epidermis atrophy and stratum corneum decrease were seen in both the experimental group and the control group, skin appendages were seen in the experimental group, but there were no skin appendages in the control group. Dermis degeneration occurred in both groups at 48 hours after frostbite rewarming, and the dermis of the experimental group was intact, while that of the control group was discontinuous. At 72 hours after frostbite rewarming, the number of nuclei of vascular endothelial cells in the experimental group was significantly more than that in the control group. The endothelial cell counts at 24, 48 and 72 hours after frostbite rewarming in the experimental group were (3.05 ±0.27)×10⁷/L, (4.29 ±0.31) ×10⁷/L and (5.14 ±0.21) ×10⁷/L respectively, while those in the control group were (3.62 ±0.14)×10⁷/L, (4.87 ±0.69) ×10⁷/L and (5.90 ±0.56) ×10⁷/L respectively. With the increase of rewarming time, the number of endothelial cells in the two groups increased gradually, and the differences were statistically significant (F=72.49, 233.30; P < 0.05). At different phase points, there were significant differences between the experimental group and the control group (t =7.26, 2.97, 4.92; P<0.05).

By simulating the frostbite model of rats and giving early rewarming treatment, it is found that Danhong rewarming solution can reduce the damage rate of vascular endothelial cells and the damage of microcirculation of frostbite tissue. It can be seen that Danhong rewarming solution can be used in the treatment of early frostbite, and its curative effect is better than normal rewarming solution.