Figure 2.

Nociceptive responses in EP1 receptor–deficient mice. (a) Acetic acid–induced stretching. The number of stretches was counted for 20 minutes immediately after 0.7% acetic acid injection intraperitoneally. Piroxicam (5 mg/kg subcutaneously) or vehicle was administered 30 minutes before acetic acid treatment. n = 8 for each group. ^AP < 0.01. (b) PBQ-induced stretching. Stretching behaviors were induced by injection of 0.02% PBQ intraperitoneally. The number of stretches was counted from 5 to 15 minutes after PBQ treatment. n = 9 EP1^+/– (filled bar) and n = 11 EP1^–/– (open bar) mice. ^AP < 0.05.