Figure 2. Suppression of visceral hypersensitivity by selective β₂AR antagonist.

(A) Administration of selective β₁AR antagonist atenolol at 1.5 mg or 7.5 mg/kg (i.p.) did not alter AWR scores. (B) Administration of selective β₂AR antagonist butoxamine at a dose of 1.5 mg/kg (i.p.) significantly attenuated AWR scores in NCI rats. *p < 0.05 vs. Veh. (C) Administration of selective β₃AR antagonist SR5923A at doses of 1.5 and 7.5 mg/kg (i.p.) had little effect on AWR scores in NCI rats. (D) Administration of butoxamine did not produce any effect on AWR scores in age-matched healthy rats.