目的 探讨丹参素干预心肌缺血/再灌注损伤（MIRI）大鼠的作用及其机制。方法 采用左前降支动脉闭塞30 min后再灌注3 h构建MIRI大鼠模型。将60只大鼠随机分为假手术组、模型组及丹参素5、15、25 mg/kg组，每组12只。假手术组大鼠进行相同的手术操作，LAD穿线但不结扎。丹参素组在再灌注开始时ip丹参素5、15、25 mg/kg，每天1次，连续给药14 d。将另外60只大鼠随机分为假手术组、模型组、丹参素(25 mg/kg)组、erastin组和丹参素＋erastin组，每组12只。丹参素组大鼠在再灌注开始时ip丹参素25 mg/kg，erastin组在MIR手术前1 h ip erastin 10 μmol/L，丹参素＋erastin组大鼠在再灌注开始时ip丹参素25 mg/kg，在MIR手术前1 h ip erastin 10 μmol/L，每天1次，连续给药14 d。采用试剂盒检测心肌组织中氧化应激指标超氧化物歧化酶（SOD）、谷胱甘肽活性（GSH）和丙二醛（MDA）的活性，铁的含量，炎症因子白细胞介素-6（IL-6）、白细胞介素-1β（IL-1β）和肿瘤坏死因子-α（TNF-α），肌酸激酶（CK）和乳酸脱氢酶（LDH）水平，以及α-平滑肌肌动蛋白（α-SMA）和胶原蛋白Ⅱ（Collagen Ⅱ）水平；通过心电图检测血流动力学参数左心室收缩压（LVSP）、左心室舒张末压（LVEDP）、左心室压力最大上升速率（+dp/dt_max）和左心室压力最大下降速率（−dp/dt_max）水平；采用苏木精-伊红（HE）染色观察心肌病理变化，TUNEL染色观察心肌细胞情况，Masson染色观察心肌纤维化程度；蛋白免疫印迹法检测心肌损伤关键蛋白酰基辅酶A合成酶长链家族成员4（ACSL4）、谷胱甘肽过氧化物酶4（GPX4）、核因子E2相关因子2（Nrf2）、血红素氧合酶-1（HO-1）和核Nrf2表达水平。结果 与模型组相比，丹参素组SOD及GSH活性明显升高，MDA活性和铁含量明显降低（P＜0.01）；IL-6、IL-1β和TNF-α水平明显降低（P＜0.01）；CK和LDH水平显著降低（P＜0.01）；α-SMA和Collagen Ⅱ水平显著降低（P＜0.01）；LVEDP水平显著降低， LVSP、+dp/dt_max和−dp/dt_max水平显著升高（P＜0.01）；丹参素可以有效改善细胞死亡状态，显著升高ACSL4、Nrf2、HO-1以及核Nrf2表达水平（P＜0.01），显著降低GPX4表达水平（P＜0.01）。结论 丹参素通过Nrf2/HO-1通路抑制缺血/再灌注诱导的铁死亡从而减轻心肌损伤。

Objective To explore the effect and mechanism of danshensu in intervening in myocardial injury in rats with myocardial ischemia/reperfusion injury (MIRI). Methods MIRI rat model was established by occlusion of the left anterior descending artery for 30 min followed by reperfusion for 3 h. 60 Rats were randomly divided into sham operation group, model group and danshensu 5, 15, 25 mg/kg groups, with 12 rats in each group. The rats in the sham operation group underwent the same surgical procedure, and LAD was threaded but not ligated. Danshensu groups were intraperitoneally injected with danshensu 5, 15 and 25 mg/kg at the beginning of reperfusion, once daily for 14 d. Another 60 rats were randomly divided into sham operation group, model group, danshensu (25 mg/kg) group, erastin group and danshensu + erastin group, with 12 rats in each group. Rats in the danshensu group were intraperitoneally injected with 25 mg/kg danshensu at the beginning of reperfusion. Rats in the erastin group were intraperitoneally injected with 10 μmol/L erastin 1 h before MIR operation. Rats in the danshensu + erastin group were intraperitoneally injected with 25 mg/kg danshensu at the beginning of reperfusion. Rats in the erastin group were intraperitoneally injected with 10 μmol/L erastin 1 h before MIR operation, once daily for 14 d. The activity of superoxide dismutase (SOD), glutathione (GSH) and malondialdehyde (MDA), the content of iron, the levels of inflammatory factors interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), creatine kinase (CK) and lactate dehydrogenase (LDH), and the levels of α-smooth muscle actin (α-SMA) and Collagen Ⅱ in myocardial tissue were detected by the kit. The levels of left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), left ventricular pressure maximum rise rate (+dp/dt_max) and left ventricular pressure maximum decline rate (−dp/dt_max) were detected by electrocardiogram. Hematoxylin-eosin (HE) staining was used to observe the pathological changes of myocardium, TUNEL staining was used to observe the myocardial cells, and Masson staining was used to observe the degree of myocardial fibrosis. Western blotting was used to detect the key proteins of myocardial injury, including acyl-CoA synthetase long chain family member 4 (ACSL4), glutathione peroxidase 4 (GPX4), nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 and nuclear Nrf2. Results Compared with the model group, the activities of SOD and GSH in the danshensu group were significantly increased, and the MDA activity and iron content were significantly decreased (P < 0.01). The levels of IL-6, IL-1β, and TNF-α were significantly decreased (P< 0.01). The levels of CK and LDH were significantly decreased (P< 0.01). The levels of α-SMA and Collagen II were significantly decreased (P< 0.01). The level of LVEDP was significantly decreased, and the levels of LVSP, +dp/dt_max and −dp/dt_max were significantly increased (P < 0.01). Danshensu could effectively improve the state of cell death, significantly increase the expression levels of ACSL4, Nrf2, HO-1 and nuclear Nrf2 (P< 0.01), and significantly reduce the expression level of GPX4 (P< 0.01). Conclusion Danshensu attenuates myocardial injury by inhibiting ischemia/reperfusion induced ferroptosis through the Nrf2/HO-1 pathway.

R285.5

河南省高等学校重点科研项目（23A360018）