methylcellulose and Anemia--Hemolytic

The rhesus monkey was evaluated in its haemopoietic and histological response to intraperitoneal injections of methylcellulose. The haematologic alterations included a mild haemolytic anaemia, lymphopaenia, monocytosis, a shortened survival of Cr51 -labelled autologous erythrocytes (17 . 1 vs 13 . 3 days, P less than 0.025) and normoblastic hyperplasia of the bone marrow. There was a diffuse sequestration of the polymer in the phagocytic cells of the spleen, liver, bone marrow, lymph nodes and adrenal glands. The renal glomerular endothelium also consistently stored this material. Overt splenomegaly was not induced. The monkey appears to present, along with other animals, a rather species-specific response to methylcellulose that is accompanied by fundamental responses observable in all subjects.

Topics: Anemia, Hemolytic; Animals; Bone Marrow; Erythrocytes; Lymphocytes; Macaca mulatta; Macrophages; Male; Methylcellulose; Phagocytosis; Spleen

Extensive hepatic erythropoiesis, granulocytopoiesis and megakaryocytopoiesis occur in adult mice given methylcellulose (MC). This appears to be a compensatory response to MC induced hemolytic anemia and thrombocytopenia. The present study was undertaken to evaluate the effects of whole body irradiation (WBI) upon established hepatic hematopoiesis (HH) as well as its effect when given before the induction of HH. Established hepatic erythroid and granulocytic foci were significantly decreased 24 hours after 100 or 300 rads. The DO for erythroid and granulocytic foci was 107 +/- 10 rads and 95 +/- 20 rads respectively, similar to those reported for murine marrow and spleen cell CFUS. Megakaryocytes were more radioresistant, gradually declining over 7 days to 50% of control values following 100 rads and with a DO of 347 +/- 7 rads; suggesting a differential radiation sensitivity compared to erythroid and granulocytic foci. WBI, 100 and 300 rads, given before MC failed to prevent subsequent development of HH although both marrow and spleen responses were reduced. Hepatic granulocytic foci and marrow peroxidase positive cells were reduced by such treatment while erythroid and megakaryocytic foci were similar to controls. This suggests that irradiation damaged stem cells responded to MC with increased erythropoiesis and megakaryocytopoiesis at the expense of granulopoiesis.

Topics: Anemia, Hemolytic; Animals; Dose-Response Relationship, Radiation; Erythropoiesis; Female; Granulocytes; Hematopoiesis; Liver; Megakaryocytes; Methylcellulose; Mice; Organ Size; Radiation Dosage; Thrombocytopenia

This study was designed to determine the effect of methylcellulose (MC)-induced reticuloendothelial (RE) hypertrophy on neutrophils and hematopoietic stem cells and to contrast its overall hematologic effect in the mouse to the more frequently studied rat model. Mice were given MC 3 times/wk and studies were done at 2, 3, and 4 wk, with maximal hematologic change by 2 wk. A stable, but incompletely compensated hemolytic anemia developed which was accompanied by a significant shift of erythropoiesis from marrow to spleen. Thrombocytopenia developed as did neutrophilia, accompanied by an increased number of marrow neutrophil precursors. Extramedullary hematopoiesis was observed in the liver. The number of cells forming spleen colonies in irradiated recipients increased in the spleen but not in marrow. The number of cells producing granulocyte and macrophage colonies in semisolid media increased in spleen and marrow. Splenectomized mice, treated with MC, developed changes very similar to intact mice. Thus, it appears that all three major hematopoietic lines may be destroyed by the MC-hypertrophied RE system. The mouse differs from the rat in its hematologic response to MC by destroying cells in organs other than the spleen, by increasing neutrophil production, by developing hepatic hematopoiesis, and by developing all changes more rapidly.

Topics: Anemia, Hemolytic; Animals; Female; Hematopoiesis; Hematopoietic Stem Cells; Liver; Male; Methylcellulose; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Neutrophils; Organ Size; Spleen; Splenectomy; Time Factors

Splenomegaly accompanied by anaemia, increased reticulocyte and decreased thrombocyte counts, was induced in Wistar rats by a long-term intraperitoneal administration of methylcellulose. Compared to controls, hypersplenic rats showed significantly enhanced utilization of 59-Fe by red cells and increased titre of erythropoietin. After the exposure of rats to hypoxic hypoxia corresponding to an altitude of 7,000 m for 6 h, no difference in the erythropoietin titre was found in either group. The results suggest that experimental hypersplenism alone does not affect the production of erythropoietin and does not stimulate the formation of an inhibitor of erythropoietin or erythropoiesis. The increased titre of erythropoietin and enhanced utilization of radioiron by red cells in rats with hypersplenism were found to be due to haemolytic anaemia leading to the stimulation of erythropoiesis.

Topics: Anemia, Hemolytic; Animals; Erythrocytes; Erythropoiesis; Erythropoietin; Hypersplenism; Hypoxia; Iron; Male; Methylcellulose; Rats

Topics: Anemia, Hemolytic; Animals; Blood Platelets; Cell Nucleus; Cytoplasm; Hematopoietic System; Lymphocytes; Macrophages; Male; Methylcellulose; Microscopy, Electron; Plasma Cells; Rats; Spleen; Splenomegaly

Topics: Anemia, Hemolytic; Animals; Bilirubin; Chromium Isotopes; Erythrocytes; Female; Hemoglobinometry; Hepatomegaly; Liver; Male; Methylcellulose; Phagocytosis; Rats; Spleen; Splenectomy; Splenomegaly

Topics: Anemia; Anemia, Hemolytic; Animals; Injections, Intravenous; Methylcellulose; Rats

Topics: Anemia; Anemia, Hemolytic; Animals; Hypercholesterolemia; Injections, Intraperitoneal; Kidney Diseases; Methylcellulose; Rats; Splenomegaly