Time course of expression of fibrin-induced IL-8 by HUVEC. HUVEC monolayers were treated with fibrin (1 mg/mL) or with control media at various times. The supernatants from control cell (c sup) or fibrin treated cells (FN sup) and cell lysates from control cells (c lys) or fibrin treated cells (FN lys) were collected and measured for IL-8 antigen. Each data point represents the mean of IL-8 ng/ 1 × 10⁶ cells ± SD of duplicate samples. The results were representative of two separate experiments.