[Changes in the kinetics of the hemoglobin, total protein and DNA content in rat erythroid cells in experimental anemia. II. The bone marrow].

Cytophotometry and population analysis of rat bone marrow erythroid cells, during anaemia induced by phenylhydrazin (4-8 days after the beginning of infections), revealed that in the period of restoration of erythron after the rats acute anaemia in the bone marrow blood formation the reciprocally complementary processes of microcytosis, macrocytosis and normal erythropoiesis occur. These processes are based on the normally functioning regulation mechanisms and on the reserve mechanisms, including DNA hyper-replication, which are turned on in the extreme conditions. The various paths of the bone marrow erythroid cells development during anaemia, the means and rates of the micro- and macrocytes formation and part of each line of the erythrocyte development in the restoration of blood cells quantity and haemoglobin homeostasis are analysed. It is suggested that mechanisms of the reserve erythropoiesis, activated during the acute anaemia of adult animals, could function also during the process of normal primary erythropoiesis of embryos.