Increased permeability of bovine aortic endothelial cell monolayers in response to a thromboxane A2-mimetic

The present study was designed to investigate the ability of thromboxane to modulate the clearance rate of 125I-albumin through bovine aortic endothelial cell (BAEC) monolayer grown on polycarbonate micropore membrane. Stimulation of BAEC with the TXA2 mimetic U44069 (10(-8), 10(-7) and 10(-6) M) elicited a dose-dependent increase of labeled albumin passage across BAEC monolayers. This effect was markedly reduced by the TXA2 antagonist L655240 (10(-7) and 10(-6) M). Our results suggest that TXA2 may modulate the permeability of endothelial cells directly through activation of specific receptors.