造血現象の核学的研究

I. 赤血球発生に就て

抄録

A study is made of the process of erythropoiesis of the bone marrow of a white rat (Rattus norvegicus var. albus) on the basis of its prints, sections, and supervital specimens. The results obtained are as follows:
1. In the pre-orthochromatic stage, erythropoiesis follows only a normal mitotic process. But some erythroblasts in the orthochromatic stage reveal frequently an abnormal mitosis where tetrad like chromosomes appear; also amitosis, although in comparatively few instances, is always observed. It is noteworthy that this stage shows rather few instances of normal mitosis.
2. The number of chromosomes generally maintains 42, except for the orthochromatic stage. One of the abnormal types in the orthochromatic stage shows the chromosomes 20-24 numbered on a nuclear plate.
3. As the differentiation proceeds, the chromosome takes a round shape and decreases its size. In the orthochromatic stage it shows a decrease in chromonomes, oligoneme phenomen, suggesting marked changes developed in shape and size.
4. The size of the resting nucleus shows a gradual diminution of about 1:1/2:1/4:1/8; the shape tends to change from an oval to regular globe.
5. It is revealed on karyometry that the indifferentiated stage, the basophilic stage, the polychromatophilic stage, and the orthochromatic stage can be classified on the basis of nuclear volume. Since each stage demonstrates cell division, it is considered that there develop at least the cells for 5 stage in erythropoiesis.
6. The mechanism of disappearance of nucleus from normoblast has been understood due to enucleation. By enucleation it is meant that there develops a fluid space between nuclear membran and cytoplasm, which grandually increases in size resulting in washing off of the nucleus. This mechanism has been found analogous to that of ovulation.
7. The cytoplasm isolated from the nucleus, i. e., young erythrocyte looks cup-shaped at first with a uniform rough structure. Then it seems to develop the membrane all over its surface, showing a gradual change of the stroma into a dense structure.
8. Many of the naked nuclei isolated from the cytoplasm are observed to be taken in the phagocytes, such as the cells of reticuloendothelium, and the histiocytes in the bone marrow, resulting in an alteration into so many globular ones. The mechanism of formation of platelets from the naked nucleus has not been obscured.