EBA permeability of HUVEC monolayers. The diffusion of EBA from the luminal buffer in the Transwell to the abluminal buffer in the lower well is shown as mg albumin/minute/cm² monolayer from 60 minutes before until 40 minutes after exposure to 0.1 U/mL thrombin in HAH buffer (black bars) or to HAH alone (shaded bars). Samples were taken at several time points before and after treatment; the 0 time point is equivalent to the start of the 5-minute treatment. Thrombin exposure resulted in a rapid increase in monolayer permeability to EBA, which was sustained for the duration of these measurements.