Development and Migration of Megakaryocyte during Hepatic Hemopoiesis in Human Fetuses.
- Author:
Won Bok LEE
1
;
Chang Whun LEE
;
Bong Soo CHUNG
;
Bum Soo KIM
;
Dea Jin KIM
;
Sung Soo KIM
;
Kyung Yong KIM
Author Information
1. Department of Anatomy, College of Medicine, Chung -Ang University, Heuk Suk Dong, Dong Jak Ku, Seoul, Korea. whitefox@cau.ac.kr
- Publication Type:Original Article
- Keywords:
Fetal liver;
Megakaryocytopoiesis;
Migration;
Emperipolesis
- MeSH:
Blood Platelets;
Cell Communication;
Cytoplasm;
Emperipolesis;
Endoplasmic Reticulum, Rough;
Epithelium;
Erythroblasts;
Fetus*;
Humans*;
Liver;
Megakaryocyte Progenitor Cells;
Megakaryocytes*;
Membranes;
Mitochondria;
Polyribosomes;
Pregnancy;
Thrombopoiesis
- From:Korean Journal of Anatomy
2002;35(4):285-296
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
Liver tissuses obtained from 5 human fetuses between 11 weeks and 23 weeks of gestation during the high activity of hepatic hemopoiesis were observed with transmission electron microscope using continuous series of thin sections. The objective of present study was to evaluate ultrastructures of megakaryopoietic cells, the migration of extravascular megakaryocyte into the sinusoidal lumen and the relevence between a migrated megakaryocyte and a Kupffer cell. Immature megakaryocytes were usually observed between growing hepatic laminae and within hepatic sinusoids. A megakaryoblast contained numerous polyribosomes, rather large mitochondria, short tubular elements of rough endoplasmic reticulum and small granules. Moreover, demarcation tubules and a few small specific granules were observed in immature megakaryocytes. The nucleus was mononuclear but frequently indented. With maturation, the nuclei were multilobulated. In the cytoplasm, in contrast to the decrease in polyribosomes and rough endoplasmic reticulum, the numerous specific granules and well -developed demarcation membrane system were predominant. Thereafter cytoplasmic zonation was observed clearly in maturing and mature megakaryocytes. Some megakaryocytes passed through the sinusoidal lining epithelium and into the hepatic sinusoids. The cell to cell interaction was often found as adhesion between migrated megakaryocyte and Kupffer cell, and erythroblasts within megakaryocyte (emperipolesis). These results suggest that intravascular megakaryopoiesis in addition to extravascular megakaryopoiesis occurs to produce platelet during the human fetal liver.
