Concentration-dependent inhibitory effect of hydrocortisone (HC) on MCP-1 secretion from U1 cells stimulated by different agents. Cells cultivated with medium alone, PMA (10 nmol/L), IL-6 (0.24 nmol/L), and IFN-γ (1.5 nmol/L) were coincubated with decreasing concentrations (ranging from 100 to 1 nmol/L) of hydrocortisone. After 72 hours, culture supernatants were harvested and stored at −80°C until tested for MCP-1 content. Mean values of duplicate cultures from one of three independent experiments are shown. Intersample variability was ≤10%.