Dopamine modulates LPS-induced macrophage cytokine secretion. MDM were treated with different concentrations of dopamine (grey bars, 20 nM, 200 nM, 2 μM, and 20 μM) in conjunction with 1 ng/mL of LPS. Control cells (Control, blue bars) were treated with LPS only, while untreated MDM were treated with vehicle (Untx, white bars). Supernatants were collected after 24 hrs of treatment and analyzed for IL-6 (A, B, n = 11), CCL2 (C, D, n = 10), TNF-α (E, F, n = 12), CXCL8 (G, H, n = 10) and IL-10 (I, J, n = 10) by ELISA. The dot graphs (A, C, E, G, I) show the concentration of each cytokine in the culture medium after 24 hours for all donors examined, demonstrating the inter-donor variability in the secretion of each cytokine. Bar graphs (B, D, F, H, I) represent the mean of the dopamine mediated fold change in cytokines from all donors relative to the control (LPS only), which was set to 1. Significance was determined using a Wilcoxon Signed Rank Test (B, D) or two–tailed Student's t-test (H). * P >0.05, ** P >0.01, *** P >0.001.