碱性成纤维细胞生长因子对柯萨奇病毒B_3性心肌炎小鼠心肌氧化应激的影响

Effect of basic fibroblast growth factor on oxidative stress of myocardium in mice of coxsackievirus B_3 induced viral myocarditis

目的研究碱性成纤维细胞生长因子(bFGF)对柯萨奇病毒B_3(CVB_3)所致病毒性心肌炎(VMC)小鼠心肌氧化应激的影响。方法雄性Balb/c小鼠通过腹腔接种CVB_3复制VMC模型。75只雄性Balb/c小鼠随机分为5组(每组15只):正常对照组、VMC组及bFGF低、中、高剂量干预组(bFGF给药采用肌肉注射,bFGF低、中、高剂量干预组的bFGF剂量分别为1 000.0、2 000.0、4 000.0 IU·kg^(-1),1次/d,共6次;bFGF的首次给药为腹腔接种CVB_3的同时肌肉注射bFGF)。于腹腔接种CVB_3后第7天处死小鼠。用光镜观察心肌组织的病理变化;用分光光度法测定心肌组织的超氧阴离子(O_2^-)、过氧化氢(H_2O_2)、羟自由基(·OH)、丙二醛(MDA)含量;用酶联免疫吸附法测定心肌组织的金属硫蛋白(MT)含量及血清的心肌肌钙蛋白Ⅰ(cTnⅠ)含量;用逆转录-实时荧光定量聚合酶链反应方法检测心肌组织的MT-ⅠmRNA、MT-ⅡmRNA表达。结果 VMC组心肌组织的O_2^-、H_2O_2、·OH、MDA含量及病理积分、血清cTnI含量明显高于正常对照组(P<0.01),心肌组织MT-ⅠmRNA、MT-ⅡmRNA表达水平及MT含量明显低于正常对照组(P<0.01);bFGF低、中、高剂量3个干预组心肌组织的O_2^-、H_2O_2、·OH、MDA含量及病理积分、血清cTnI含量明显低于VMC组(P<0.01),心肌组织MT-I mRNA、MT-ⅡmRNA表达水平及MT含量明显高于VMC组(P<0.01),且与bFGF的剂量呈量效关系。结论 bFGF抑制CVB_3导致心肌氧化应激而减轻CVB_3对心肌的损伤,与其拮抗CVB_3抑制心肌合成MT而增加心肌清除O_2^-、H_2O_2、·OH的能力有关。

Objective To study the effect of basic fibroblast growth factor （bFGF） on oxidative stress of myocardium in mice of coxsackievirus B3 （ CVB3 ） induced viral myocarditis （VMC）. Methods Male Balb/c mice were inoculated intraperitoneally with CVB3 to reconstruct an animal model of myocarditis. Seventy-five male Balb/c mice were randomly divided into five groups （n = 15） ： normal control group, VMC group, bFGF low-dose, middle-dose, high-dose intervention groups, bFGF was administrated by intramuscular injection （ira）. The mice were inoculated intraperitoneally with CVB3 while im bFGF （ the dosage of bFGF in three intervention groups were 1 000. 0,2 000. 0, 4 000. 0 IU · kg-1 , respectively） each day one time for six times. All mice were sacrificed at the seventh day after ＂noculated intraperitoneally with CVB3. The pathological changes of myocardial tissues were observed with light microscope. The contents of superoxide anion （02-）, hydrogen peroxide （H202）, hydroxyl radical （ · OH） and malon- dialdehyde （MDA） were determined by spectrophotometry in myocardial tissues. The contents of metallothionein （MT） and cardiac troponin I （cTn I ） were determined by enzyme-linked immunosorbant assay method in myocardial tissues and serum respectively. The expressions of myocardial MT- I mRNA and MT- 11 mRNA were detected by reverse transcription-real time fluorescent quantitative polymerase chain reaction method in myocardial tissues. Results The contents of 02- , H202, · OH, MDA and pathological scores in myocardial tissues, the content of cTn I in serum in VMC group were significantly higher than those in normal control group （ P 〈 0. 01 ）, the expressive levels of MT- I mRNA, MT- lI mRNA and content of MT in myocardial tissues in VMC group were significantly lower than those in normal control group （ P 〈 0.01 ）. The contents of 02 - , H2 02, · OH, MDA and pathological scores in myocardial tissues, the content of cTn I in serum in bFGF three intervention groups were significantly lower than those in VMC group （P 〈0. 01 ）, the expressive levels of MT- I mRNA, MT-]I mRNA and content of MT in myocardial tissues in bFGF three intervention groups were significantly higher than those in VMC group （P 〈 0. 01 ）, the changes were obviously dose-dependent with bFGF in bFGF three imervention groups. Conclusion bFGF inhibited the oxidative stress in myocardium induced by CVB3 , and thereby reduced injury of myocardium induced by CVB3 , this was related to bFGF antagonized the inhibitory effect of CVB3 on the synthesis of MT in myocardium, thereby enhanced capabilities of scavenging of O2 - , H2O2, OH in myocardium.