Hyperbaric oxygen treatment induces platelet aggregation and protein release, without altering expression of activation molecules

Objectives: To investigate the effect of hyperbaric oxygen (HBO) on platelet physiology. Design and methods: Human platelets were exposed to HBO (97.7% O2, balance CO2 at 2.2 ata) or control (CON; 5% CO2, balance air at 1 ata) for 90 min, and analyzed for aggregation, protein release, {radical dot}NO production, and activation. Results: HBO induced 29.8 ± 3.0% of platelets to aggregate compared with CON (5.5 ± 0.9%). Proteins observed to be released in greater abundance from HBO- compared with CON-treated platelets included 14-3-3 zeta and α-2-macroglobulin. Release of {radical dot}NO by platelets was unaffected following exposure to HBO, as was platelet activation as measured by surface expression of PECAM-1, CD62P and the activated form of αIIBβIIIa. Conclusions: Exposure to HBO induces both platelet aggregation and protein release. Further study will better define the precise mechanisms and effects of HBO on platelet activation. © 2009 The Canadian Society of Clinical Chemists.