(A) Concentration-dependent increase in IL-8 production stimulated with Et-1. Confluent CNS-ECs were exposed to different concentrations of Et-1, as well as media alone. After 72 hours, supernatant samples were analyzed for IL-8 production using the IL-8 ELISA technique. Data are the mean ± SEM of triplicate samples. The first point is Et-1 at zero concentration. The results represent one of three experiments performed. (B) Eleven experiments using Et-1 (100 nmol/L)-treated and untreated cell (72 hours) supernatants were analyzed for IL-8 production. Results for the two groups are significantly different (P < .001).