Figure 1

Acute mechanical and thermal pain and inflammatory- and chemical-induced pain in iNOS^-/- and n/i/eNOS^-/- mice. (A) Formalin test. Mice were injected intraplantarly with formalin (5% (v/v), 20 μL). Values represent the duration (sec) of licking and biting responses for each 5-min interval, from 0-5 min (1st phase), for 10-35 min (2nd-1 phase) and for 35-60 min (2nd-2 phase) (n = 8 animals/group). (B) Innocuous mechanical stimuli test. Values indicate the threshold (g) to elicit paw withdrawal behavior in response to mechanical stimuli (WT mice and n/i/eNOS^-/-mice, n = 9, iNOS^-/-mice n = 8 animals) (C) Tail-flick test. Values represent the latency (sec) for animals to flick their tail away from the heat source (n = 8 animals/group) (D) Visceral pain in response to acetic acid (0.8% (v/v)). Values represent the numbers of abdominal stretches (writhes) (n = 8 animals/group). All data are presented as means ± SEM. Statistical analysis were determined by two-way repeated ANOVA (A) or two-way ANOVA (B, C, D) with Tukey's test, *P < 0.05, **P < 0.01 vs. WT mice, #P < 0.05, ##P < 0.01 vs. iNOS^-/-mice.