The Alteration of Intracellular Enzyme Activities during Stimulation on Erythropoiesis

In vivo and in vitro Studies

Abstract

We have analyzed the alteration of hexokinase (Hx), pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G6PD), malate dehydrogenase (MDH) and δ-aminolevulinate systhetase (δ-ALA s) activities of erythrocytes, bone marrow and spleen cells during erythropoietic stimulation. The studies in vivo were carried out on female Wistar rats that received an intraperitoneal injection of acetylphenylhydrazine (APH) at a dose of 60 mg/kg body weight. Peripheral blood and bone marrow cells were collected daily from the beginning to the recovery stage of anemia. Increasing of erythrocyte Hx and G6PD activities were observed from 4 to 6 days after APH injection. Both Hx and G6PD activities of bone marrow cells decreased at 3 days after the injection and recovered to normal activities at 6 days after the injection. We have also examined the enzyme activities of suspended spleen or bone marrow cells after stimulation with 1 U/ml erythropoietin (Epo) in vitro. PK and G6PD activities of bone marrow cells were stimulated at 2-4 hours after exposure to Epp. The increase of MDH and δ-ALA s activities were detected after 24 hours of incubation with Epo. These data suggest that the alteration of glycolytic enzyme activities were induced earlier than that of MDH or δ-ALA s in rat bone marrow and spleen cells under the erythropoietic stimulation.