LY-uptake after C3-pretreatment in the absence and presence of thrombin.

<p>Non-confluent grown BCEC were exposed to the hydrophilic Lucifer Yellow dye (2.5% for 5 min) in a PBS-buffer containing 2 mM EGTA. Left panels represent the fluorescence signal of LY while the cells are visualized by differential interference contrast (DIC) microscopy (right panels). (A) Uptake of LY in control condition (N = 4, n = 20). (B) LY-uptake is blocked in BCEC treated with thrombin (2 U/ml) for 5 min (N = 4, n = 20). (C) LY-uptake after pretreatment with C3 (2 g/ml) for 3 hours (N = 4, n = 20). (D) C3 prevents significant LY-uptake after thrombin-treatment (N = 4, n = 20). The approximate percentage of cells that accumulated the dye was determined for each condition by manually counting the number of LY-positive and LY-negative cells (n = 200 cells). Cells were considered LY-positive or -negative as indicated in the box.