The effect of acute hyperoxia in vivo on NF kappa B expression in human PBMC

The mechanisms of hyperbaric oxygen (HBO) therapy have not been fully elucidated. It is presumed that breathing 100% oxygen at pressure generates free radicals and the cellular response to these may confer protection. A crucial signalling molecule, nuclear transcription factor kappa B (NFκB), translocates from the cytoplasm to the nucleus and activates a raft of pathways in response to various stimuli, and plays a role in inflammatory processes. This study focussed upon the expression of NFκB in isolated human peripheral blood mononuclear cells (PBMC) following HBO. Ten healthy male volunteers underwent a single HBO treatment, breathing 100% oxygen at a pressure of 2.8 ATA for 1 h. EDTA blood samples were taken pre‐, post‐ and 4‐h post‐HBO. PBMC were isolated, nuclear extracts prepared and assayed using a NFkBp50 transcription factor ELISA. Mean NFκB expression of 0.27 (0.20–0.34, 95%CI) absorbance units (mg protein) −1 was observed pre‐HBO and this increased to 0.29 (0.20–0.38, 95%CI) immediately post‐HBO. A significant increase in NFκB expression within PBMC was observed 4‐h post‐HBO, in comparison to pre‐HBO (mean 0.38, 0.30–0.47, 95%CI, p  = 0.027). This study demonstrates that HBO induces NFκB activation in human PBMC, which could be a crucial step in the mechanism of HBO treatment. Copyright © 2010 John Wiley & Sons, Ltd.