Morphometric Studies of Megakaryocytes in Human and Rat Fetal, Infantile and Adult Hematopoiesis. II. Observations on rat fetuses and adult rats

In author morphological study of megakaryocytes of rats, a comparative study was made on the size and ultrastructure of megakaryocytes of rat fetuses and adult rats. Furthermore, in relation to megakaryocytes, a comparison was also made on platelet count of rats during the fetal stage and after birth.
The mean megakaryocyte size during the fetal stage was significantly smaller than that of the adult. Study on the ultrastructure revealed a slight difference in DMS between the fetus and the adult.
The electron density of granules in the megakaryocytes was higher in the adult than in the fetus. The platelet count was found to be significantly smaller during the fetal stage than after birth.