Adrenalectomized (Adx) rats fail to develop OR486-induced hypersensitivity. In Sham (Shm), but not Adx, animals, sustained systemic OR486 administration produces (A) mechanical allodynia, (B) mechanical hyperalgesia, and (C) thermal hyperalgesia. N = 11 (5 males and 6 females) for Shm/vehicle (Veh) and N = 12 (6 males and 6 females) for all other groups. Data are expressed as mean ± SEM. ***P < 0.001, **P < 0.01, *P < 0.05 different from Shm/Veh. BL = Baseline.