Fig. 1.

Production of IFN-γ, IL-12, IL-1β, IL-4 and IL-10 by mouse spleen cells 20 min after treatment with heroin. BALB/c mice were treated with heroin (□) or PBS (▪) and their spleen cells were stimulated with irradiated allogeneic cells (production of IFN-γ, IL-4 and IL-10) or their PEC were stimulated with LPS/IFN-γ (production of IL-12 and IL-1β). The production of IL-12 and IL-1β was measured after 48-h stimulation, IFN-γ after 72 h stimulation and IL-4 and IL-10 after 96-h stimulation by ELISA. Each bar represents the mean ± s.e. from three independent experiments. Values with asterisks represent significant (*P < 0·05, **P < 0·01) difference between PBS and heroin-treated group.