Comparative characteristics of the pigs’ and rats’ early erythropoiesis

摘要

Investigation of the pig’s and rat’s embryos erythropoiesis showed that in rats, in distinct with pigs, there was not a significant intra-embryonic mesenchymal erythropoiesis. First time it was revealed, that in pigs during the mesenchymal megaloblastic erythropoiesis in a part of the cells an extrusion of nuclei and a formation of the primitive erythrocytes are possible to appear. According to our data got, their amount in pigs made up not more, than 2-2.5% of the whole erythroid cells population. The given type of the cells is being determined on the 15-25th days of the pig embryo’s development and almost completely disappeared by the 35th days of gestation. Nevertheless, the nucleated and non-nucleated primary erythrocytes that formed generations vary on their size, most often big cells, the megaloblasts and megalocytes, could be observed. The megaloblastic erythropoiesis in rats was revealed on the 12th stage of gestation, when only megaloblasts were appeared in the yolk sac vessels, whereas erythrocytes were being revealed already on the 13th stage of that. On the 13-14 stages, when the hepatic erythropoiesis is already started, the erythrocytes number was being dramatically increased, making up more than 70% of the rats erythroid cells population. Herein, the megalocytes number in rats was a rather high, attaining up to 43% of the erythrocytes population, while the megalocytes number in the pigs’ hepatic erythropoiesis did not exceed 10% of the whole erythrocytes population. At the early stages of the rats’ ontogenetic development almost a complete absence of DNA synthesis was observed. The latter, in our opinion, is a consequence of the more intensive erythropoieses during the pig’s physiological development process. At the same time, absence of the hemopoietic cells’ hypertetraploid population in rats confirms our suggestion. On the benefit of our suggestion the lesser values of hemoglobin content in the erythroid cells of the early erythropoiesis in rats vs. the analogical indices in pigs indicate as well