Typical tracings of the mouse gastric fundus contracted with prostaglandin F2α (PGF, 0.3 μM) showing (A) the relaxations induced by electrical field stimulation (EFS, 0.5 – 4 Hz, pulses of 1 ms during 10 s and 8 Hz, pulses of 1 ms during 2 min) and 1 μM NO, added as acidified NaNO2, and the effect of L-NOARG (300 μM) on the relaxations to EFS and NO. (B) shows the effect of L-NOARG for n=6 experiments. Results are expressed as percentage decrease of the prostaglandin F2α-induced contraction and shown as mean±s.e.mean. *P<0.05 is considered as significantly different from control, Student's t-test for paired values.