Effect of acute and chronic naloxone treatment on serum IgG anti-KLH antibody response.

Animals were immunized with either 50 μg KLH and killed after 1 week (panel A) or 2 weeks (panel C), or with 100 μg KLH and killed after 1 week (panel B) or 2 weeks (panel D). Results are expressed as mean ± SE of 10 animals per group. * = P < .01 versus saline control.