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: In the development of imaging probes for tumour hypoxia, nitroimidazoles have received particular attention as hypoxia markers because of their unique behaviour in hypoxic environments. 2-nitroimidazole (azomycin) was originally found to be an antibiotic against anaerobic bacteria and protozoa in 1953 . Nitroaromatics are selectively reduced by nitroreductase enzymes under hypoxic conditions to form hydroxylamine intermediates that can bind irreversibly to cellular nucleophilic groups in proteins or DNA. This property permits their antibacterial action. The irreversible retention of nitroimidazoles in the cells is also a prerequisite to differentiate between normoxic and hypoxic tissues  (Fig. 1A).
Affiliation: Centre de Biophysique Moléculaire, CNRS UPR, Orléans, France.