胎儿肝脏发育早期肝细胞一氧化氮合酶的表达

Expression of Nitric Oxide Synthase in Hepatocytes during Early Development of Fetal Liver

目的探讨胎儿肝脏发育早期肝细胞中一氧化氮合酶的表达情况。方法取43例胎儿肝脏组织,经甲醛固定和石蜡包埋,行HE染色。显微镜下观察胎儿发育不同时段肝脏的组织学表现,免疫组织化学及图像分析方法分别检测其一氧化氮合酶异构体(nNOS、iNOS、eNOS)的表达水平。应用SPSS12.0软件进行统计学分析。结果在6～9周胚胎中未见肝细胞,第12周时可见大量肝细胞及肝索,16周时肝小叶已显现,但无汇管区,28周时肝脏正常结构形成。免疫组织化学结果显示,在胎肝发育第12周时,nNOS、iNOS和eNOS在肝细胞中均呈阳性表达;在第16周和28周时,nNOS无表达,iNOS表达呈明显下降趋势,而eNOS表达则显著升高。结论肝细胞NOS表达在胎肝发育早期呈时间差异性,对肝组织的成熟可能起重要作用。

Objective To investigate the nitric oxide synthase（NOS）expression in hepatocytes during early development of fetal liver.Methods Forty-three cases of fetal liver tissues were fixed by formaldehyde and embedded in paraffin for hematoxylineosin staining.Histological appearance of liver was observed in different stages of human fetal liver development,then expression of NOS isoforms（nNOS,iNOS and eNOS）were detected by immunohistochemistry and image analysis.Results No hepatocyte was found in the embryo of 6-9 weeks,but a lot of hepatocytes and cords were found at 12th week.Liver lobular was seen clearly at 16th week without portal triad.Liver normal structure had formed in 28th week.Immunohistochemical reaction showed that nNOS,iNOS and eNOS expression were all positive at 12th week.But no expression of nNOS was found in 16 weeks and 28 weeks,while iNOS expression decreased and eNOS expression increased significantly.Conclusions NOS expression of hepatocytes is differential timely during early development of fetal liver,which can play an important role in maturation of liver tissues.