TNF modulates Et-1–induced IL-8 production. Confluent CNS-ECs were exposed to Et-1 (10⁻⁷ mol/L), TNF (10 pg/mL), or IL-10 (10 ng/mL) separately or in the combinations of TNF + Et-1 or IL-10 + Et-1. After 72 hours, the culture supernatant was examined for IL-8 production using the ELISA technique. Results are the mean ± SEM of triplicate cultures. The data represent one of three experiments.