Effects of pretreatment with the NOS inhibitors 7-NINA, AG, L-NIO and L-NAME on CFA-induced thermal hyperalgesia assessed by the paw withdrawal latency (PWL) tests. Following CFA injection, PWLs were markedly decreased within 6 h and continued until 24 h post injection in the ipsilateral hindpaw (A, ***P < 0.001, NS + CFA vs NS + NS). Pretreatment with 7-NINA, AG and L-NAME, but not L-NIO, dramatically attenuated thermal hyperalgesia in mice receiving CFA throughout the observation period (A, ###
P < 0.001, inhibitor + CFA vs NS + CFA). None of the inhibitors altered pain thresholds in mice receiving NS (B, inhibitor + NS vs NS + NS). n = 4 for each group.