Waxman HS. Stimulation of globin synthesis: relative responsiveness of reticulocytes and nucleated erythroid cells.
J Clin Invest 1970;
49:701-7. [PMID:
5443172 PMCID:
PMC322525 DOI:
10.1172/jci106282]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The effects of iron, cobalt, hemin, and plasma on hemoglobin synthesis by suspensions of rabbit reticulocytes and nucleated bone marrow cells were studied. L-Leucine-(14)C and sodium pyruvate-3-(14)C were employed to measure globin and heme synthesis, respectively. Normal plasma (or serum) was found to stimulate the rate of globin synthesis in both systems. The stimulatory effects of iron and hemin were additive to those of plasma or serum only in the reticulocytes. Cobaltous ion, at concentrations less than 1.0 mmole/liter, was found to stimulate globin synthesis by reticulocytes as effectively as ferrous ion; cobalt was inhibitory only at concentrations greater than 3.0-5.0 mmoles/liter. Heme synthesis by reticulocytes was inhibited at all concentrations employed (0.2-5.0 mmoles/liter). In bone marrow nucleated erythroid cells, globin synthesis was markedly enhanced by exogenous hemin. In contrast to reticulocytes, however, bone marrow cells were unresponsive to either cobalt or transferrin-bound iron. Possible implications of these findings on regulation of the rate and mechanism of iron uptake and hemoglobin synthesis in vivo are discussed.
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