The effect of Et receptor antagonists. The CNS-EC were pretreated with 200 nmol/L ET_A receptor antagonist, BQ610, or 200 nmol/L ET_B receptor antagonist, BQ788, for 20 minutes, followed by 1 hour of incubation with 100 nmol/L Et-1. In all of the experiments presented, cells were treated with Et-1 for 1 hour. Subsequently, RNA was isolated from the cells, and the RPA was performed. The results are visualized by autoradiography; protected fragments corresponding to IL-8 (181 bp) and GAPDH (96 bp) are shown (A). The data in this and subsequent figures were calculated as the ratios of IL-8 mRNA to GAPDH mRNA and are presented relative to the control values (B). The data presented are representative of 1 of 3 replicate experiments performed. The error bars represent the SEM.