Why is the partial oxygen pressure of human tissues a crucial parameter? Small molecules and hypoxia.
Bottom Line: The oxygen partial pressure (pO(2)), which is a key component of the physiological state of an organ, results from the balance between oxygen delivery and its consumption.More importantly we emphasize the discrepancy between in vivo and in vitro tissue and cells oxygen status which can have detrimental effects on experimental outcome.It is important to realize that most of the experiments performed in so-called normoxia might be dangerously misleading.
Affiliation: Centre de Biophysique Moléculaire, CNRS UPR, Orléans, France.Show MeSH
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Mentions: As an example, angiogenin is up-regulated in various types of human cancers and takes part in tumour progression by stimulating both angiogenesis and cancer cell proliferation .The release of angiogenin from various cells present in the skin is very sensitive to oxygen pressure (Fig. 8). Strong hypoxia (less than 7.6 mmHg or 1% O2) induces an increase in angiogenin secretion for the cell lines derived from fibroblasts, human skin microvascular endothelial cells, normal melanocytes and keratinocytes. But skin physioxia (22.8 mmHg of O2 or 3% O2) is already able to lead to the same increase of angiogenin by keratinocytes and normal melanocyte cell line. On the opposite, this pO2 does not modify the angiogenin expression by human skin microvascular endothelial cell line or fibroblasts. Here again, results from normoxia does not reflect the real behaviour of cells in physioxia. Furthermore, this example points out the difference of sensitivity to oxygen pressure of distinct cell lines.
Affiliation: Centre de Biophysique Moléculaire, CNRS UPR, Orléans, France.