INFLUENCE OF HYPOXIA AND HYPOXIA-REOXYGENATION ON ENDOTHELIAL P-SELECTIN EXPRESSION

P-selectin is an endothelial adhesion molecule involved in the initial step of the neutrophil recruitment. We investigated the effect of hyp oxia (95% N-2, 5% CO2) and of hypoxia-reoxygenation (95% air, 5% CO2) on the expression of P-selectin by human umbilical vein endothelial ce lls (HUVEC). P-selectin expression was detected by immunolabelling and quantified by flow cytometric analysis.Our data indicate that hypoxia induces an increase in P-selectin expression with a maximum reached a fter 90 minutes. A hypoxic exposure of 90 minutes results in a highly significant increase compared to normoxia (p<0.001, n=13). Furthermore , when a reoxygenation period follows 90 minutes of hypoxia, the initi ally elevated levels of P-selectin are dramatically enhanced with a ma ximum obtained after 60 minutes of reoxygenation.