乌司他丁预处理对骨骼肌高热损伤的保护作用

摘要

目的：探讨乌司他丁预处理对大鼠骨骼肌高热损伤的影响。方法：体外培养大鼠骨骼肌细胞分为7组：正常对照组（ C 组）：常规培养，不给予任何处理；高热处理组（ H 组）：将细胞置于42℃培养箱中2 h，随后转入37℃培养箱按常规培养；乌司他丁处理组（U 组）：细胞以含乌司他丁终浓度1250 U/mL 的培养液于37℃培养箱中作用1 h ，余同正常对照组；不同浓度乌司他丁预处理＋高热处理组，共4组分别为Ⅰ组、Ⅱ组、Ⅲ组和Ⅳ组：细胞在高热处理前分别以含乌司他丁终浓度312、625、1250、2500 U/mL 的培养液于37℃培养箱中作用1 h ，余同H组处理。处理完毕后MTT法测定细胞活力， LDH法测定细胞损伤，测定细胞内SOD活性和MDA水平。结果：与H 组相比，乌司他丁预处理各组MTT值升高（P＜0．05），LDH释放量减少（P＜0．05），培养细胞内的SOD活性明显升高，而培养细胞的MDA生成量减少（P＜0．05）。乌司他丁预处理各组间，各指标差异无显著性（P＞0．05）。结论：乌司他丁预处理对骨骼肌细胞高热损伤有保护作用，可能与其抑制自由基的生成及清除有关。%Objective To investigate the effect of Ulinastatin preconditioning on hyperthermia induced rat skeletal muscle injury and the possible mechanism. Methods Cultured skeletal muscle cells were divided into 7 groups: control group (Group C), as normal culture; hyperthermia treated group (Group H), in which cells were exposed to 42℃for 2 hours then transfered to normal culture; ulinastatin preconditioned group (Group U), which were only preconditioned 1 hour by the final concentration of ulinastatin at 1 250 U/mL; and four different concentration of ulinastatin preconditioned+hyperthermia treated groups (Group Ⅰ, Ⅱ, Ⅲ, Ⅳ), in which cells were preconditioned 1 hour by the final concentration of ulinastatin at 312 , 625, 1250, 2 500 U/mL, respectively. And then, all the four groups were exposed to 42℃for 2 hours. MTT assay and LDH leakage were performed to study the cytotoxicity. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) formation were measured to reflect the activity of antioxidase. Results Compared with Group H, MTT value in ulinastatin preconditioned group in GroupⅠ, Ⅱ,Ⅲ, Ⅳsignificantly increased (P<0.05) LDH leakage significantly decreased (P<0.05). And the activity of SOD in cultured cells significantly increased (P < 0.05), the content of cellular MDA was also significantly decreased (P<0.05). But there were no significant difference among Group Ⅰ, Ⅱ,Ⅲ,Ⅳ(P>0.05). Conclusion Ulinastatin preconditioning may have protective effect against hyperthermia induced skeletal muscle injury and it may be related to its ability of inhibiting radical production and promoting radical scavenging.