Studies on the biological effects of ozone: 9. Effects of ozone on human platelets.

During the course of ozonated autohaemotherapy (O3-AHT) using heparin as an anticoagulant, it was occasionally observed that a few clots were retained in the filter during blood reinfusion. This observation prompted an investigation on the effect of ozone (O3) on human platelets. We have now shown, both by biochemical and morphological criteria, that heparin in the presence of O3 can promote platelet aggregation. In contrast, after Ca(2+) chelation with citrate, platelet aggregation is much reduced. The potential role of the transient formation of hydrogen peroxide (H2O2) in the presence of Ca2+ with the possible expression of adhesion molecules is briefly discussed.