THE RATIO OF FORMATION OF PROSTACYCLIN THROMBOXANE A(2) IN HUVEC DECREASED IN EACH SUBSEQUENT PASSAGE/

In this study, we analyzed the antioxidative potential (SOD-, GSH-Px-a ctivity) and the basal, H2O2- and ATP-stimulated formation of PGI(2) a nd TXA(2) in human umbilical vein endothelial cells (HUVEC) of differe nt passages. The subcultivation of cells partly represents the process of aging. Both subcultivation of the cells and the H2O2 incubation di d not significantly influence the activity of SOD and GSH-Px. H2O2 (0. 1 mM and 1.0 mM) stimulated the generation of PGI(2) and TXA(2) in the cell passages time dependently. The formation ratio of PGI(2)/TXA(2) changed from 640:1 (0.1 mM H2O2) or 430:1 (1.0 mM H2O2, 40 min incubat ion) at the 1st passage, to 23:1 and 17:1, respectively, at the 4th pa ssage. This resulted from the reduction of the PGI(2) synthesis connec ted with more pronounced TXA, formation. The same behavior was found i n the basal and ATP-stimulated eicosanoid formation. Based on this, th e age-dependent activation of the oxygen radical formation could be re sponsible for the modified eicosanoid metabolism resulting in vascular complications in the elderly.