大鼠肝细胞线粒体形态的三维重建

THREE DIMENSIONAL RECONSTRUCTION OF MITOCHONDRIA IN RAT HEPATOCYTE

目的研究同一细胞内不同形态线粒体的数量、大小和超微结构。方法用三维重建和体视学测量的方法，研究成年大鼠肝细胞线粒体的形态类型。结果肝细胞线粒体按形态可分为５个基本类型：Ⅰ型（球形、椭球形和盘状）线粒体约占线粒体总数的２１．４％；Ⅱ型（杆状）约占３２．４％；Ⅲ型（不规则形）约占２３．８％，Ⅳ型（分支形）约占１９．６％，Ⅴ型（出芽形）仅占２．８％。Ⅰ～Ⅴ型线粒体的平均体积分别为０．１１、０．２１、０．３２、０．５１和０．６４μｍ３。体现学分析显示，各型线粒体的体积密度有差异（Ｐ＜０．０５或Ｐ＜０．０１），Ⅱ型线粒体体积密度最大，然后是Ⅲ、Ⅳ和Ⅰ型，Ⅴ型线粒体体积密度最小。Ⅰ、Ⅱ和Ⅴ型线粒体嵴膜密度均高于Ⅲ或Ⅳ型（Ｐ＜０．０５）。结论肝细胞内不同形态的线粒体都占有一定的比例，他们不仅体积差异很大，其超微结构亦有不同。

Objective\ To examine the number,size and ultrastructure of the different forms of mitochondria in a cell.Methods\ Morphological types of the mitochondria in rat hepatocyte were studied by three dimensional reconstruction and stereological analyses.Results\ The mitochondria may be classified into five basic types according to their morphological characteristic.The numbers(%)of type Ⅰ(sphere, ellipses and disc),type Ⅱ(rods),typeⅢ(irregulars),typeⅣ(branches)and typeⅤ(budding)were 21 4%,32 4%,23 8%,19 6% and 2 8%,respectively.And their average volume were 0 11μm 3,0 21μm 3,0 ^32μm 3,0 51μm 3 and 0 64μm 3,respectively.Stereological analyses showed that there were significant difference in volume,density and crista membrane density among five types of mitochondria( P <0 05 or P <0 01).The volume density of mitochondria type Ⅱ was the highest,that of type Ⅴ the lowest and that of type Ⅲ,type Ⅳ and type Ⅰ the medium.Mitochondrial cristamembrane density of type Ⅰ,type Ⅱ and type Ⅴ was higher than both that of type Ⅲ and type Ⅳ.Conclusion\ Each type of mitochondria kept a suitable proportion in normal rat liver cell.There were significant difference not only in volume among different forms of mitochondria,but also in ultrastructure.