Dopamine modulates macrophage cytokine secretion. Monocyte-derived macrophages (MDM) were treated with different concentrations of dopamine (grey bars, 20 nM, 200 nM, 2 uM, and 20 uM) for 24 hrs. Control cells were treated with media (Untx, white bars). Supernatants were collected after treatment and analyzed for IL-6 (A, B, n = 11), CCL2, (C, D,n = 13) and CXCL8 (E, F, n = 6) by ELISA. The dot graphs (A, C, E) 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) represent the mean of the dopamine–mediated fold change in cytokine from all donors relative to the control (Untx), which is 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.