新生小鼠轮状病毒腹泻诱导型一氧化氮合酶mRNA的表达及其意义

Expression of nitric oxide synthase mRNA in neonatal mice with rotavirus diarrhea

目的研究新生小鼠轮状病毒(rotavirus,RV)腹泻小肠诱导型一氧化氮合酶mRNA(iNOS mRNA)的表达,探讨其在RV腹泻发病机制中的作用。方法48只3 d新生昆明小鼠随机分为实验组(32只)与对照组(16只),实验组经口灌入0.2 ml(2×108 PFU)含RV培养液,对照组灌入0.2 ml不含病毒的培养液,分别于接种后相应时间点观察腹泻情况并评分。ELISA方法检测粪便RV抗原,并取肠黏膜观察病理学变化,采用实时荧光PCR检测实验组iNOS mRNA表达变化,对腹泻程度及iNOS表达进行相关性分析。结果实验组小鼠接种病毒后24 h均出现腹泻,在接种后第4天达高峰,第10天完全恢复正常,粪便ELISA检测RV抗原均为阳性,小肠病理改变为上皮细胞空泡样变性;小肠iNOS mRNA的表达显著增强,乳鼠肠iNOS mRNA的表达变化趋势与腹泻发生程度有相关性(r=0.708,P<0.05)。对照组未出现腹泻,病理改变不明显。结论新生小鼠RV腹泻小肠iNOS mRNA表达增强,乳鼠肠iNOS mRNA的表达变化与腹泻发生程度存在正相关,提示其在介导RV腹泻中发挥重要作用。

Objective To study the expression of nitric oxide synthase（iNOS） mRNA of mice intestine and possible mechanism of rotavirus diarrhea.Methods Forty-eight three-day-old Kunming mice were randomly divided into the experiment group（n = 32） and the control group（n = 16）.Mice of the experiment group were administered orally with 2 × 108 PFU of SA11 virus while mice of the control group were processed with culture medium.Diarrhea and virus shedding were recorded.Histological changes of the intestines samples were observed under light microscope.iNOS mRNA of the intestine was determined by real time fluorescent PCR.The correlation between diarrhea severity and iNOS mRNA expression was analyzed.Results In experimental group,diarrhea occurred by 24 hours,became most severe by 96 hours and completely recovered after 10 days.All the rotavirus antigen of stool was positive.The pathological changes of the small intestine were extensive vacuolation.iNOS mRNA expression was correlated with the severity of diarrhea and reached the highest level on day four,then it was down-regulated and dropped to the lowest level on day ten.iNOS mRNA expression paralleled the occurrence and severity of diarrhea.There is correlation between the iNOS mRNA expression and diarrhea（r = 0.708,P〈0.05）.No diarrhea and pathological changes of small intestine were observed in the control group.Conclusions The expression of iNOS mRNA in small intestine of mice with diarrhea was increased.There was a positive correlation between the severity of diarrhea and iNOS mRNA expression.These findings imply that iNOS mRNA may play an important role in rotavirus-induced diarrhea.