目的 探討丹參素干預心肌缺血/再灌注損傷（MIRI）大鼠的作用及其機制。方法 采用左前降支動脈閉塞30 min后再灌注3 h構建MIRI大鼠模型。將60只大鼠隨機分為假手術組、模型組及丹參素5、15、25 mg/kg組，每組12只。假手術組大鼠進行相同的手術操作，LAD穿線但不結扎。丹參素組在再灌注開始時ip丹參素5、15、25 mg/kg，每天1次，連續(xù)給藥14 d。將另外60只大鼠隨機分為假手術組、模型組、丹參素(25 mg/kg)組、erastin組和丹參素＋erastin組，每組12只。丹參素組大鼠在再灌注開始時ip丹參素25 mg/kg，erastin組在MIR手術前1 h ip erastin 10 μmol/L，丹參素＋erastin組大鼠在再灌注開始時ip丹參素25 mg/kg，在MIR手術前1 h ip erastin 10 μmol/L，每天1次，連續(xù)給藥14 d。采用試劑盒檢測心肌組織中氧化應激指標超氧化物歧化酶（SOD）、谷胱甘肽活性（GSH）和丙二醛（MDA）的活性，鐵的含量，炎癥因子白細胞介素-6（IL-6）、白細胞介素-1β（IL-1β）和腫瘤壞死因子-α（TNF-α），肌酸激酶（CK）和乳酸脫氫酶（LDH）水平，以及α-平滑肌肌動蛋白（α-SMA）和膠原蛋白Ⅱ（Collagen Ⅱ）水平；通過心電圖檢測血流動力學參數(shù)左心室收縮壓（LVSP）、左心室舒張末壓（LVEDP）、左心室壓力最大上升速率（+dp/dt_max）和左心室壓力最大下降速率（−dp/dt_max）水平；采用蘇木精-伊紅（HE）染色觀察心肌病理變化，TUNEL染色觀察心肌細胞情況，Masson染色觀察心肌纖維化程度；蛋白免疫印跡法檢測心肌損傷關鍵蛋白?；o酶A合成酶長鏈家族成員4（ACSL4）、谷胱甘肽過氧化物酶4（GPX4）、核因子E2相關因子2（Nrf2）、血紅素氧合酶-1（HO-1）和核Nrf2表達水平。結果 與模型組相比，丹參素組SOD及GSH活性明顯升高，MDA活性和鐵含量明顯降低（P＜0.01）；IL-6、IL-1β和TNF-α水平明顯降低（P＜0.01）；CK和LDH水平顯著降低（P＜0.01）；α-SMA和Collagen Ⅱ水平顯著降低（P＜0.01）；LVEDP水平顯著降低， LVSP、+dp/dt_max和−dp/dt_max水平顯著升高（P＜0.01）；丹參素可以有效改善細胞死亡狀態(tài)，顯著升高ACSL4、Nrf2、HO-1以及核Nrf2表達水平（P＜0.01），顯著降低GPX4表達水平（P＜0.01）。結論 丹參素通過Nrf2/HO-1通路抑制缺血/再灌注誘導的鐵死亡從而減輕心肌損傷。

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

河南省高等學校重點科研項目（23A360018）