Blockade of Adrenal Medulla-Derived Epinephrine Potentiates Bee Venom-Induced Antinociception in the Mouse Formalin Test: Involvement of Peripheral β-Adrenoceptors
Figure 6
Graphs summarizing the effect of administration of β-adrenoceptor subtype antagonists on the antinociceptive effect of DBV on formalin-induced nociceptive behaviors. (a) DBV treatment (Veh + DBV + F) significantly decreased pain behaviors compared with vehicle group (Veh + Veh + F, ***). Coadministration of atenolol with vehicle [Atenolol (1, 5 mg) + Veh + F] did not change pain behaviors as compared to the vehicle-injected group during either the early or late phase. High dose of atenolol pretreatment with DBV [Atenolol (5 mg) + DBV + F] significantly decreased the formalin-induced pain responses as compared to DBV-treated group at the late phase (#). (b) Similarly, DBV (Veh + DBV + F) significantly decreased pain behaviors compared to the vehicle group (Veh + Veh + F, **). Intraperitoneal injection of ICI-118,551 with vehicle [ICI-118,551 (2, 4 mg) + Veh + F] had no effect on pain behaviors as compared to the control group during either the early or late phase, whereas administration of a high dose of ICI-118,551 in combination with DBV [ICI-118,551 (4 mg) + DBV + F] significantly decreased the pain responses as compared to the DBV-treated group during the late phase (#) but not during the early phase of the formalin test.
