Kinetics of IL-8 production by Et-1–stimulated CNS-ECs. Confluent CNS-ECs were cultured in the absence (□) or presence (▵) of Et-1 (10⁻⁷ mol/L). At 24-, 48-, and 72-hour intervals, supernatants were examined for IL-8 production using the ELISA technique. Data are the mean ± SEM of quadruplicate samples. This is one of three representative experiments.