Fig. 7.

To examine the effect of mucosal supernatant on H₂O₂ production, PBL were incubated for 20 min at 37°C in mucosal supernatant from sacs incubated in Krebs buffer alone (control) or in acidified Krebs buffer (pH 5, 3 h) (supernatant). The supernatant of the acidified mucosal sac caused a 2-fold increase in H₂O₂ production by PBL. When using antagonists or antibodies, PBL were pretreated with the antagonist or antibody for 30 min before exposure to the supernatant. The increase in H₂O₂ levels was not affected by a CGRP antagonist (CGRP_8–37, 10⁻⁶ M) or by IL-8 immunoneutralization by an IL-8 antibody (1:200). The increased H₂O₂ levels, however, were significantly reduced by a PAF receptor antagonist (CV3988, 10⁻⁵ M) and by an NK-1 receptor antagonist (10⁻⁵ M) (*P < 0.05 ANOVA). Data represent means + SE of 8 experiments.