Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1996-1-25
pubmed:abstractText
Erythropoiesis is controlled by different regulators. Interleukin 3, granulocyte-macrophage colony-stimulating factor and stem cell factor play regulatory functions in the early steps of erythropoiesis. Erythropoietin (Epo) is the main factor which acts positively on the last steps of the production of erythrocytes in mammals. Epo is specific for the erythroid progenitor cells and has only little effect on other cells. The target cells for Epo are the erythroid progenitors (BFUe and CFUe). Epo acts on these progenitors through surface receptors specific for Epo. Epo induces the proliferation and differentiation of erythroid progenitors leading finally to reticulocytes. During this process, certain conditions are required to permit this differentiation: progenitors must be present in sufficient numbers, the bone marrow environment must be normal, and nutrients such as folic acid, vitamin B12 and particularly iron must be available. Elemental iron is an absolute requirement for adequate haemoglobin formation. Indeed, in a normal adult, without any stimulation, the bone marrow synthesizes 4 x 10(14) molecules of haemoglobin per second, each molecule containing four atoms of iron, which roughly corresponds to 20 mg iron. On the other hand, erythropoiesis is negatively regulated by several cytokines. These are macrophage-derived cytokines, including tumour necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), interleukin-6 (IL-6) and transforming growth factor-beta (TGF-beta). All these factors are elevated in the inflammatory state and are implicated in the pathogenesis of anaemia of chronic disease. TNF-alpha has an inhibitory effect on erythroid progenitors either directly or mediated by interferon-beta (INF-beta). IL-1 inhibits erythropoiesis in vivo in mice and in vitro in humans.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0931-0509
pubmed:author
pubmed:issnType
Print
pubmed:volume
10 Suppl 6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
27-30
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Cellular mechanism of resistance to erythropoietin.
pubmed:affiliation
Laboratoire d'Hématologie, Hôpital Raymond Poincaré, Garches, France.
pubmed:publicationType
Journal Article, In Vitro, Review