Objective: To investigate the protective effects of salidroside on endothelial cells in rats with frostbite after chronic hypoxia. Methods: Healthy male SD rats, randomly divided into 3 groups with 10 rats in each group, which included the sham injury group, the model group, and the model +salidroside group. The rats in each group were placed in a composite low-pressure chamber to simulate a environment with a pressure of 54.1 kpa and a temperature of 23~25°C. The rats were exposed to hypoxia under these conditions for 14 days, during the experimental time the rats in the model+salidroside group were treated with 50 mg/kg salidroside daily. After the rats were removed from the low-pressure chamber, except for the sham injury group, frozen iron sheets were applied tightly to the back of the rats for 30 s, supplemented with low temperature for frostbite modeling. Blood and skin tissues were collected at 12 hours after modeling for testing. The structural changes in tissue and vascular endothelial cells were observed in the frostbite region. Vascular endothelial cell particulate EMP levels were detected. The levels of ICAM-1, sEPCR, vWF, ET-1 and NO secretion were determined. The expression levels of HIF-1α, p-PI3K, p-Akt and VEGF were detected by Western blot. Results: Salidroside could effectively reduce skin collapse in frostbitten areas. It could reduce the injury of frostbitten tissues, and improve the subcutaneous tissue necrosis and inflammatory cell infiltration. The autophagy of vascular endothelial cells was reduced. Compared with the model group (0.250±0.165)%, the expression of EMPs in the model+salidroside group (2.453±0.196)% was increased significantly (P＜0.01). In addition, the contents of NO (2.622±0.219)pg/ml was also significantly higher than that of the model group (1.616±0.152)pg/ml (P＜0.01), and the content of vWF (233.50±13.43)pg/ml was lower than that of the model group (315.60±8.78)pg/ml (P＜0.05). There was no significant difference in the levels of ICAM-1, sEPCR and ET-1. Salidroside significantly decreased the expressions of p-PI3K, p-Akt, VEGF and HIF-1α protein in vascular endothelial cells of rats with frostbite (P＜0.01). Conclusion: Salidroside can reduce endothelial cell damage, reduce endothelial cell autophagy and promote endothelial cell regeneration. Based on the PI3K/Akt pathway, salidroside has a good protective effect on endothelial cells of rats with frostbite after chronic hypoxia.
目的: 研究红景天苷对慢性低氧后冻伤大鼠血管内皮细胞的保护作用。方法: 健康雄性SD大鼠,随机分为3组(n=10):假伤组,模型组,模型+红景天苷组。各组大鼠置于复合低压舱内,设置舱内压力为54.1 kpa,温度为23~25℃。大鼠在此条件下低氧暴露14 d,期间模型+红景天苷组大鼠每日灌服50 mg/kg红景天苷。大鼠从低压舱中取出后,除了假伤组以外,均使用冷冻过的铁片紧贴大鼠背部30 s,辅以低温进行冻伤造模。造模后12 h采集血液及皮肤组织进行试验。观察冻伤区域组织与血管内皮细胞结构变化;检测血管内皮细胞微粒EMP水平;检测血管内皮细胞损伤标示物ICAM-1、sEPCR、vWF、ET-1水平与NO分泌情况;WB检测HIF-1α、p-PI3K、p-Akt及VEGF表达水平。结果: 红景天苷有效减轻冻伤区域皮肤塌陷现象。改善皮下组织坏死及炎性细胞浸润情况。减少血管内皮细胞自噬。与模型组(0.250±0.165)%相比,模型+红景天苷组(2.453±0.196)%显著增强EMPs表达(P＜0.01)。并且NO含量(2.622±0.219)pg/ml也显著高于模型组(1.616±0.152)pg/ml(P＜0.01),vWF含量(233.50±13.43)pg/ml低于模型组(315.60±8.78)pg/ml(P＜0.05),ICAM-1、sEPCR、ET-1含量无明显差异。红景天苷显著降低冻伤大鼠血管内皮细胞p-PI3K、 p-Akt、VEGF及HIF-1α蛋白表达(P＜0.01)。结论: 红景天苷可减轻血管内皮细胞损伤,减少血管内皮细胞自噬,促进血管内皮细胞再生。红景天苷基于PI3K/Akt通路对慢性低氧后冻伤大鼠血管内皮细胞具有良好的保护作用而降低冻伤组织的损伤。.
Keywords: EMPs; PI3K/Akt; frostbite; rats; salidroside; vascular endothelial cell.