Effect of SCp2 cell number and substratum on ET-induced IL-6 secretion and NO production. SCg6 cells were plated and treated as described in Methods. The medium was collected 24 h after ET treatment and assayed for IL-6 secretion (A&B) and nitrite production (C&D) from SCp2 cells (A, C) on plastic or (B, D) on SCg6 monolayer. IL-6 secretion or nitrite production in control cells are depicted by open bars, and those in ET-treated cells are depicted by closed bars. The 0 plating density in (B) and (D) represents data from SCg6 cells alone in the absence of SCp2 cells. Data represents the average of two independent experiments ± SEM. (*) denotes significant differences between ET and non-ET treatment within each time point (p < 0.05) and letters denote significant differences among SCp2 cell plating densities within treatment (p < 0.05).