사람태아 간장의 적혈구조혈세포에 관한 핵 계측학적 연구

Abstract

This study was carried out for the quantitative analysis about the counts and the diameters of hepatic erythropoietic cell nuclei in 51 cases of human embryonic and fetal livers from 5 weeks to 40 weeks of gestation under a light microscope. The purposes of this study were to obtain informations about the initiation time of hepatic hemopoiesis, and the stages of activity and the distribution of nuclear diameters of hepatic erythropoietic cells in human embryos and fetuses. The results obtained were as follows. 1. Hepatic erythropoiesis began in 6 weeks of gestation, and many proerythroblasts and undifferentiated cells more than 7㎛ in nuclear diameter appeared in primitive hepatic cords. Megakaryocytes appeared around central veins in the 7-week embryo and a few granulocytes were seen in hepatic cords and in mesenchymal tissue around large vessels in the 8-week embryo. 2. Hepatic erythropoietic activity was rapidly increasing at the embryonic period from 6 weeks to 10 weeks to gestation, and many erythroblasts were observed in primitive hepatic cords from 7 weeks to 8 weeks of gestation. 3. Hepatic erythropoietic activity was maintained at the highest level from 10 weeks to 21 weeks of gestation, and various hepatic erythropoietic cells showed between 3 and 8㎛ in nuclear diameters. 4. The gestation period from 22 weeks to 40 weeks of gestation was the last period in hepatic erythropoiesis and in that period erythropoictic activity began to decrease definitely. With age, immature hepatic erythropoietic cells became to disappear and only mature erythroblasts were seen. Erythropoietic activity decreased rapidly from 33 week to 40 weeks of gestation.