低硒小鼠柯萨奇B组病毒重叠感染与心肌损伤关系的研究

目的 探讨Se缺乏、CVB4、CVB3m重叠感染与心肌损伤的关系。方法 采用低Se及相对低蛋白合成饲料、饮用含Se元素水与不含硒的水的方法，饲养小鼠及其所产的幼鼠，于出生7d，幼鼠先后感染CVB4，CVB3m，2型病毒感染间隔为7d，感染CVB3m病毒后7、14、21d分别处死小鼠，取心脏做光镜、电镜检测。结果 Se缺乏组小鼠，心肌可见轻度损伤，心肌细胞色素氧化酶活力下降。病毒感染7d后，低Se 病毒组小鼠与补Se 病毒组小鼠比较，低硒病毒组血清CVB3m抗体效价1:256，补硒病毒组中和抗体效价为1:512，低硒组感染病毒的毒力增加，心肌中病毒分离滴度低硒组明显高于补硒组，心肌细胞色素氧化进一步下降，心肌损伤检出率达63.6%，心肌变性坏死的数量多，损伤面积大。结论 Se缺乏是克山病心肌损害因素之一，而柯萨奇B组2型病毒重叠感染在克山病心肌损伤过程中的作用也不能忽视。硒具有某种程度的抗病毒作用或抑病毒作用。

Experimental study on mouse myocardial injury induced by Se-deficiency and viral superinfection of CVB4 and CVB3m

Objective To investigate relation between Se-deficiency andsuperinfection of both CVB4 and CVB3m in mouse myocardial injury.Methods The mice (Kunming line) were divided into 4 groups on the Se contents and superinfection of Coxsackie virus B (CVB). Group1:Se-deficient,without CVB; Group 2: Se-rich without CVB; Group 3:, Se-deficient with CVB; and Group 4: Se-rich with CVB. The mice were fed with Se-deficient food containing lower protein and Se was applied by adding the Se into the drinking water for Se-rich group. For the CVB superinfection groups, the 7-day-old baby mice were inoculated with CVB4. After 1 week interval, the mice inoculated with CVB4 were superinfected with CVB3m .The mice were killed and their myocardial tissue sections were examined under lightmicroscope and electronic microscope at day 7,day 14 and day 21,respectively after CVB3m superinfection.Results The result showed that the myocardium was lightly damaged and the activity of cytochrome oxidase of myocardium decreased in Group 2 compared with those in Group 1.The result also indicated that myocardial injury rate was as high as 63.6%,and the myocardial injury and necrosis area was larger in Grope 4 than those in Group 2 and Group 3.The serological test showed that the titer of neutralizing antibody against CVB3m was 1:256 and 1:512 in Group 4 and in Group 3,respectively.All the results suggested that the interaction between Se-deficiency and superinfection of CVB4and CVB3m intensified the mouse myocardial damage. Conclusions Se-deficiency was one of the factors for myocardial injury in Keshan Disease and the superinfection of two types of CVBs might play a role in the incidence of Keshan Disease and selenium might play roles of antivirus and virus repression to some extent.