Diurnal variation of circulating human myeloid progenitor cells.
We investigated whether human circulating myeloid progenitor cells (CFU(c)) exhibit diurnal variation. Peripheral venous blood samples were drawn every 3 h from each of the nine healthy male volunteers. Blood mononuclear cells were harvested by the Ficoll-Hypaque method. CFU(c) content of blood was determined by the soft agar cloning assay. Human placental conditioned medium (HPCM) was used as colony stimulating factor. We found a 24 h cyclic variation of colonies/10(5) mononuclear cells plated with a maximum at 9 a.m. (P < 0.01). Analysis of the colonies by in situ staining indicated that this variation could be attributed almost entirely to colonies composed of eosinophilic cells (representative of CFU(eos)). Neutrophil/macrophage colonies (representative of CFU(G,M)) exhibited a trend toward a 9 a.m. maximum, but this variation was not statistically significant. We conclude that time of blood collection should be standardized in experiments measuring human peripheral blood CFU(c).
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- Neutrophils
- Myeloid Progenitor Cells
- Male
- Macrophages
- Immunology
- Humans
- Colony-Forming Units Assay
- Circadian Rhythm
- Cells, Cultured
- 3201 Cardiovascular medicine and haematology
Citation
Published In
ISSN
Publication Date
Volume
Issue
Start / End Page
Location
Related Subject Headings
- Neutrophils
- Myeloid Progenitor Cells
- Male
- Macrophages
- Immunology
- Humans
- Colony-Forming Units Assay
- Circadian Rhythm
- Cells, Cultured
- 3201 Cardiovascular medicine and haematology