Figure 4
From: Effects of mu- and kappa-2 opioid receptor agonists on pain and rearing behaviors
We found that GR89,696 does not affect operant thermal outcome measures. Animals treated with either GR89,696 (1.25 × 10-4 mg/kg, subcutaneous) or vehicle (PBS, subcutaneous) prior to facial capsaicin application did not significantly differ from each other when evaluated using the six thermal operant outcome measures (N = 10). Both groups were significantly lower (*P < 0.05) than baseline values in all instances except for GR89696 in Facial Contact Duration (B) and for both GR89696 and vehicle for Facial Duration/Contact (F). Overall, this indicates that the neurogenic inflammatory pain was not inhibited following capsaicin application.