Effects of intragastric injection of NaCl (0.15 M), HCl (0.35 M), vehicle (Veh) and capsaicin (Cap, 3.2 mM) on the (A) initial rise of intragastric pressure (IGP), (B) subsequent time course of IGP and (C) fluid recovery from the stomach. NaCl, HCl, Veh and Cap were injected as 2 ml bolus. The values shown in panel A represent the IGP reached 2–3 min post-injection. The IGP values measured during the periods 9–10 min and 29–30 min post-injection (panel B) are expressed as a percentage of the initial IGP rise recorded 2–3 min post-injection, and the gastric volume recovery (panel C) measured 30 min after bolus injection is expressed as a percentage of the injection volume (2 ml). Means + SEM, n = 6–13. ** P < 0.01 versus IGP measured 2–3 min post-injection; ++ P < 0.01 versus NaCl.