Effect of acute and chronic naloxone treatment on KLH-stimulated IFN-γ production by splenocytes.

Animals were immunized with either KLH (panels A,B,C,D) or 100 μg KLH (panels E,F,G,H) and killed after 1 week (panels A,B,E,F) or 2 weeks (panels C,D,G,H). Spleen cells were cultured with 0 or 80 μg/ml KLH for 48 h (panels A,C,E,G) and 72 h (panels B,D,F,H). Acute saline control is represented by white bars; chronic saline control is represented by right-slanted striped bars; acute naloxone treatment is represented by left-slanted striped bars; chronic naloxone treatment is represented by hatched bars. Results are expressed as mean ± SE. * = P < .01 versus corresponding saline controls.