Figure 5. Electric field stimulation (EFS)-evoked non-adrenergic non-cholinergic-mediated relaxations of guinea-pig tracheal strips in vitro before and after vehicle (DMSO; A) 50 μm FM2-10 (B) 5 μm FM1-43 (C) 1 μm tetrodotoxin (TTX) (D) and 0.1 μm ω-conotoxin GVIA (E).

Tissues were first treated with 1 μm atropine to prevent cholinergic contractions and then precontracted with 10 μm histamine. Each curve represents the mean ±s.e.m. of n = 3–4 experiments and is expressed as a percentage reversal of the contraction evoked by 10 μm histamine. *P < 0.05, significantly different compared to before the treatment.