Figure 3.

Depolarization of guinea pig and human vagus nerve. (A and B) Depolarization induced by capsaicin (n = 9) (A) or prostaglandin E₂ (PGE₂; n = 4) (B) of isolated vagus nerve taken from guinea pigs exposed to either air (open triangles) or cigarette smoke (CS; solid triangles) for 8 days. (C and D) Depolarization induced by capsaicin (n = 7 nonsmoker, 13 smoker) (C) or PGE₂ (open squares, nonsmoker, n = 9; solid squares, smoker, n = 10) (D) of isolated vagus nerve taken from human smokers and nonsmokers (with no other respiratory disease). Data are presented as mean ± SE. *P < 0.05 as determined by Mann-Whitney U test.