金丝桃苷改善脓毒症模型大鼠心肌损伤作用机制研究

Mechanism of Hyperoside Improving Myocardial Injury in Model Rats with Sepsis

目的探讨金丝桃苷经缺氧诱导因子-1α/血红素加氧酶-1(HIF-1α/HO-1)信号通路对脓毒症模型大鼠心肌细胞的改善作用。方法将120只SD大鼠随机分为正常对照组(A组,等体积生理盐水)、模型组(B组,等体积生理盐水)、阳性药对照组(C组,地塞米松10 mg/kg)和金丝桃苷低、中、高剂量组(D_1组、D_2组、D_3组,10,20,40 mg/kg),各20只。腹腔注射10%水合氯醛(0.3 mL/kg)建立脓毒症大鼠模型。各组腹腔注射相应药物,给药1次,12 h后处死动物。检测大鼠的血流动力学指标;以酶联免疫吸附(ELISA)法检测血清中心肌肌钙蛋白I(cTnI)、脑钠肽(BNP)和心脏组织匀浆中肿瘤坏死因子-α(TNF-α)、白细胞介素1β(IL-1β)水平;以苏木精-伊红(HE)染色切片观察心脏结构病理变化;以免疫组化染色法测定大鼠心脏HIF-1α和HO-1蛋白表达水平。结果与A组比较,B组左心室收缩压(LVSP)、左室压最大升高率(+dp/dt_(max))、左室压最大降低率(-dp/dt_(max))、HIF-1α和HO-1水平均显著降低,左心室舒张末压(LVEDP)、cTnI、BNP、TNF-α和IL-1β水平均显著升高(P<0.05);与B组比较,C组、D_1组、D_2组、D_3组的LVSP,+dp/dt_(max),-dp/dt_(max),HIF-1α和HO-1水平均显著升高,LVEDP,cTnI,BNP,TNF-α和IL-1β的水平均显著降低,且呈剂量依赖性(P <0.05)。与C组比较,D_1组、D_2组LVSP,+dp/dt_(max),-dp/dt_(max)均显著降低,LVEDP,cTnI,BNP,TNF-α,IL-1β,HIF-1α,HO-1水平均显著升高(P <0.05),D_3组各指标无显著差异(P>0.05)。A组大鼠心脏组织结构无明显病理变化;B组大鼠心肌细胞边界模糊,可见大量炎性细胞浸润和坏死区域;D_1组、D_2组、D_3组大鼠心肌炎性细胞浸润数量减少,细胞结构及边界较B组明显好转。结论金丝桃苷对脓毒症模型大鼠的心肌损伤具有一定改善作用,其作用机制可能与金丝桃苷通过诱导HIF-1α/HO-1信号通路,激活脓毒症大鼠HIF-1α和HO-1蛋白的表达有关。

Objective To investigate the improvement effect of hyperoside on myocardial cells of septic rats through hypoxia-inducible factor-1α/heme oxygenase-1(HIF-1α/HO-1)signaling pathway.Methods Totally 120 SD rats were randomly divided into normal control group(group A,equal volume of normal saline),model group(group B,equal volume of normal saline),positive drug control group(group C,10 mg/kg of dexamethasone)and hyperoside low-dose,medium-dose and high-dose groups(groups D1,D2 and D3,10,20 and 40 mg/kg of herb-drug),20 rats in each group.The rat models with sepsis were constructed by intraperitoneal injection of 0.3 mL/kg of 10%chloral hydrate.The rats in each group were intraperitoneally injected with the corresponding drugs for once and the killed 12 h after administration.The hemodynamic indexes of rats were detected.The levels of cardiac troponin I(cTnI)and brain natriuretic peptide(BNP)in serum,the levels of tumor necrosis factor-α(TNF-α)and interleukin-1β(IL-1β)in the homogenization of cardiac tissue were detected by Enzyme linked immunosorbent assay(ELISA).The heart tissues were stained with hematoxylin eosin(HE)to observe the pathological changes of heart structure.The expression levels of HIF-1αand HO-1 protein in the hearts of rats were detected by immunohistochemical staining.Results Compared with those in group A,the left ventricular systolic pressure(LVSP),maximum increase rate of left ventricular pressure(+dp/dtmax),maximum decrease rate of left ventricular pressure(-dp/dtmax),levels of HIF-1αand HO-1 in group B were significantly decreased,while the left ventricular end diastolic pressure(LVEDP),cTnI,BNP,TNF-αand IL-1βin group B were significantly increased(P<0.05).Compared with those in group B,the LVSP,+dp/dtmax,-dp/dtmax,the levels of HIF-1αand HO-1 in groups C,D1,D2 and D3 were significantly increased,while the LVEDP,the levels of cTnI,BNP,TNF-αand IL-1βin groups C,D1,D2 and D3 were significantly decreased with a dose-dependent manner(P<0.05).Compared with those in group C,the LVSP,+dp/dtmax,-dp/dtmax in groups D1 and D2 were significantly decreased,while the LVEDP,the levels of cTnI,BNP,TNF-α,IL-1α,HIF-1αand HO-1 in groups D1 and D2 were significantly incresased(P<0.05),and those indexes in group D3 had no significant difference(P>0.05).In group A,there was no obvious pathological change in the heart tissue structure of rats.In group B,the border of cardiomyocytes was blurred,and a large number of inflammatory cell infiltration and necrotic areas were visible.In groups D1,D2 and D3,the number of inflammatory cell infiltration was decreased,and the cell structure and border were significantly improved compared with those in group B.Conclusion Hyperoside has a certain improvement effect on myocardial injury in model rats with septic,its mechanism may be that hyperoside activates the expression of HIF-1αand HO-1 proteins in septic rats by inducing the HIF-1α/HO-1 pathway.