3.1.2 COX-1 but not COX-2 signaling mediates the bradykinin-enhancing capsaicin responses
The figure 3A and B shows representative traces of the effect of either SC560 (cox-1 inhibitor) or NS398 (COX-2 inhibitor) on calcium responses upon repeated capsaicin applications in the presence of bradykinin (100nM; 3 min). The SC560; 100nM), but not the COX-2 inhibitor (NS398; 10μM), had a significant inhibitory effect on the bradykinin-induced sensitization of capsaicin-induced calcium responses in DRG neurons (Fig 3 A and B). The response ratios of first and second capsaicin responses in the presence of bradykinin + SC560 and for bradykinin + NS398 were 56.9±8.1% (*P < 0.05 by one-way ANOVA followed by a Bonferroni’s multiple comparison test) and 84.7 ± 10.6% (P >0.05), respectively (Fig 3C).