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

Abstract Objectives To investigate the effect of hyperbaric oxygen (HBO) on platelet physiology. Design and methods Human platelets were exposed to HBO (97.7% O 2 , balance CO 2 at 2.2 ata) or control (CON; 5% CO 2 , balance air at 1 ata) for 90 min, and analyzed for aggregation, protein release, 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 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 α IIB β IIIa . 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.