Heynen M J, Tricot G, Verwilghen R L
Cell Tissue Res. 1985;239(1):235-9. doi: 10.1007/BF00214924.
Late erythroblasts and reticulocytes from bone marrow of male Wistar rats were studied by electron-microscopic stereology. Late erythroblasts with morphological signs of nuclear extrusion (EN + erythroblasts) and late erythroblasts without these signs (EN-erythroblasts) were analysed separately. The volumes of mitochondria, autophagosomes, autophagocytosed mitochondria, autophagocytosed cytoplasm and degraded material inside autophagosomes were calculated per unit volume of cytoplasm. The results demonstrate that (1) the volume density of mitochondria in the cytoplasm decreases by 34% during maturation from (EN-)- to (EN +)-erythroblasts (P less than 0.001) and by 60% during differentiation from (EN +)-erythroblasts to reticulocytes (P less than 0.001), (2) a fivefold increase in the volume density of autophagosomes in the cytoplasm is noted during maturation from (EN-)- to (EN +)-erythroblasts (P less than 0.01), whereas the value of this parameter remains essentially unchanged during the subsequent differentiation to reticulocytes, (3) no mitochondria are found inside autophagosomes of (EN-)-erythroblasts, whereas mitochondria occupy 26% and 35%, respectively, of the autophagosomal volume in (EN +)-erythroblasts and in reticulocytes. Our results show that autophagocytosis of mitochondria starts at the moment of nuclear extrusion and continues in the bone marrow reticulocytes.
采用电子显微镜体视学方法研究了雄性Wistar大鼠骨髓中的晚期成红细胞和网织红细胞。分别分析了具有核挤出形态学特征的晚期成红细胞（EN +成红细胞）和不具有这些特征的晚期成红细胞（EN-成红细胞）。计算单位细胞质体积中线粒体、自噬体、被自噬的线粒体、被自噬的细胞质以及自噬体内降解物质的体积。结果表明：（1）从（EN-）成红细胞到（EN +）成红细胞成熟过程中，细胞质中线粒体的体积密度下降34%（P<0.001），从（EN +）成红细胞分化为网织红细胞过程中下降60%（P<0.001）；（2）从（EN-）成红细胞到（EN +）成红细胞成熟过程中，细胞质中自噬体的体积密度增加5倍（P<0.01），而在随后分化为网织红细胞的过程中该参数值基本保持不变；（3）（EN-）成红细胞的自噬体内未发现线粒体，而在（EN +）成红细胞和网织红细胞中，线粒体分别占自噬体体积的26%和35%。我们的结果表明，线粒体自噬始于核挤出时刻，并在骨髓网织红细胞中持续存在。
