sodium-dodecyl-sulfate and Anemia

The specific radioactivity of mouse globin mRNA in blood reticulocytes was measured after injection of [(3)H]uridine into anaemic mice up to 60h before collection of reticulocytes. From these data, the decay of the acid-soluble nucleotide pool in the marrow and the relative marrow-cell composition it is possible to build models that allow the cell life-times and half-life of mRNA in the erythroid cells of the marrow to be calculated. Best fit of models to these data favour a model with either one or two cell divisions from the onset of mRNA synthesis. The single-cell-division model has cell times of 20, 13 and 7h respectively for the basophilic erythroblast, polychromatophilic erythroblast and reticulocyte. The two-cell-division model has cell times of 12, 12, 12 and 7h for the basophilic erythroblast 1 and 2, polychromatophilic erythroblast and reticulocyte respectively. Both models have an mRNA half-life of 17h and a constant rate of mRNA synthesis until enucleation at the reticulocyte stage, when synthesis stops. A declining rate of mRNA synthesis can be accommodated in a two-cell-division model, when synthesis halves at each cell division and cell times are essentially the same as above, but mRNA half-life is either 9h in the basophilic and polychromatophilic erythroblasts and 17h in the later cells, or 10h in the basophilic erythroblasts and polychromatophilic erythroblasts and 14.5h in later cells. In all cases it is clear that mRNA synthesis occurs over a time-period of only 30-36h and that mRNA cannot be pre-synthesized in precursor erythroid cells.

Topics: Anemia; Animals; Bone Marrow; Bone Marrow Cells; Cell Division; Centrifugation, Density Gradient; Computers; Erythrocytes; Erythropoiesis; Globins; Half-Life; Hemoglobins; Mice; Models, Biological; Phenylhydrazines; Reticulocytes; Ribosomes; RNA, Messenger; Sodium Dodecyl Sulfate; Time Factors; Tritium; Uridine

Topics: Anemia; Animals; Carcinoma, Krebs 2; Centrifugation, Density Gradient; Chromatography, Gel; Evaluation Studies as Topic; Methods; Mice; Nucleoproteins; Phenylhydrazines; Polyribosomes; Rabbits; Reticulocytes; RNA, Messenger; RNA, Ribosomal; Sodium Dodecyl Sulfate; Spectrophotometry, Ultraviolet

Topics: Anemia; Animals; Antigen-Antibody Reactions; Biological Assay; Chromatography, DEAE-Cellulose; Chromatography, Gel; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; Erythrocytes; Erythropoietin; Humans; Hydrogen-Ion Concentration; Iron; Iron Radioisotopes; Mathematics; Rats; Sodium Dodecyl Sulfate; Spectrophotometry, Ultraviolet; Starvation; Urea

Topics: Anemia; Animals; Bone Marrow; Bone Marrow Cells; Centrifugation, Density Gradient; Centrifugation, Zonal; Erythrocytes; Evaluation Studies as Topic; Globins; Methods; Phenylhydrazines; Polyribosomes; Protein Biosynthesis; Rabbits; Reticulocytes; RNA, Messenger; RNA, Ribosomal; Sodium Dodecyl Sulfate; Spectrophotometry, Ultraviolet

Intact rabbit reticulocyte cells synthesize two predominant species of membrane polypeptides; at least 10 reticulocyte membrane polypeptide species are not produced by the cells. Cell-free extracts of reticulocytes, free of any membranes or membrane-bound polyribosomes, synthesize large amounts of these two membrane polypeptides; one of these polypeptides appears to be modified, probably by loss of 20-40 amino acids, after it is incorporated into the membrane. Deprivation of hemin results in inhibition of synthesis by lysates of membrane proteins, globin, and all other cytoplasmic proteins.

Topics: Acetates; Anemia; Animals; Autoradiography; Blood Proteins; Cell Membrane; Cell-Free System; Electrophoresis, Polyacrylamide Gel; Heme; Hydrogen-Ion Concentration; Iontophoresis; Methionine; Methods; Molecular Weight; Peptides; Polyribosomes; Rabbits; Reticulocytes; Sodium Dodecyl Sulfate; Sulfur Isotopes; Trypsin

Topics: Anemia; Animals; Cell-Free System; Centrifugation, Density Gradient; Ducks; Edetic Acid; Erythrocytes; Globins; Magnesium; Molecular Conformation; Phenylhydrazines; Polyribosomes; Protein Biosynthesis; Ribosomes; RNA, Messenger; Sodium Dodecyl Sulfate; Valine