Figure 5. The effect of the combination of CLCA blocker (niflumic acid) and TRPV1 inhibitor (I-RTX) on bradykinin-induced action potential responses in guinea pig airway jugular C-fibers.

A, the combination of niflumic acid (100 mM) and I-RTX (1 mM) virtually abolished the bradykinin-induced response. It was different from both niflumic acid alone (n = 5) and I-RTX alone (n = 5; *P < 0.05, Student-Newman-Keul's test for multiple comparisons), which indicates that both activation pathways were independent to each other. B, representative trace of extracellular recording in combination treatment group. The response to bradykinin was completely blocked by the combination treatment but the response to citric acid (10 mM, 200 ml) was preserved.