Effect of acute and chronic naloxone treatment on KLH-stimulated IL-4 production in vitro by splenocytes.

Animals were immunized with either 50 μg KLH (panels A,B) or 100 μg KLH (panels C,D) and killed after 1 week (panels A,C) or 2 weeks (panels B,D). Spleen cells were cultured with 0 or 80 μg/ml KLH for 72 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 saline controls.