神经生长因子在小鼠病毒性心肌炎心肌中表达的意义

Significance of nerve growth factor expression in myocardial tissue of mice with viral myocarditis

目的探讨病毒性心肌炎（VMC）发病过程中，心肌组织神经生长因子（NGF）表达的动态变化及发病机制中作用。方法70只4周龄雄性BALB／C小鼠腹腔接种0．1ml的CVB。建立VMC模型，10只同周龄同品系小鼠腹腔接种Eagle’s液作为对照组。VMC组于接种后3、7、15、30d，对照组于30d处死，采用RT-PCR、免疫组化检测心肌NGF mRNA及蛋白表达，并对NGF表达水平与心肌病变积分进行相关性分析。结果VMC组3～30d各时点心肌NGFmRNA及蛋白表达水平均明显增高，以7d时为最高，与对照组比较，差异均有显著性（P〈0.05或0.01），而且NGF蛋白表达水平与心肌病变积分呈显著正相关（r=0．90，P〈0．05）。结论NGF过度表达可能在病毒性心肌炎的发病机制中起重要作用。

Objective To investigate the dynamic changes and significance of nerve growth factor （NGF） expression in myocardial tissues of mice with viral myocarditis（VMC）. Methods Eighty four-weekold male BALB/C mice were divided into two groups randomly. Mice in the VMC group （n = 70） were inoculated intraperitoneally with 0. lml of CVB3, while mice in the control group （n = 10） were treated with 0. lml of Eagle＇ s solution. Ten infected mice were sacrificed on day 3, 7, 15 or 30 respectively after inoculation, and the control mice were killed on day 30. The expression levels of myocardial NGF mRNA and protein were examined with RT-PCR and immunohistochemistry. In addition, the correlationship between the expression levels of NGF and myocardial histopathological scores was analyzed. Results In comparison with those in control group, the expression levels of myocardial NGF mRNA and protein from day 3 to 30 in VMC group increased significantly and reached the peak level on day 7 after inoculation （P〈0.05 or 0.01）. Furthermore, the NGF protein expression levels showed significantly positive correlationship with the myocardial histopathologic scores（r = 0.90,P〈0.05）. Conclusions The excessive expression of NGF may play an important role in the pathogenesis of viral myocarditis.