Blockade of Adrenal Medulla-Derived Epinephrine Potentiates Bee Venom-Induced Antinociception in the Mouse Formalin Test: Involvement of Peripheral β-Adrenoceptors

Figure 3

Graph illustrating the effect of administration of exogenous epinephrine in adrenalectomized mice on formalin-induced nociception. Treatment with DBV in adrenalectomized mice (Veh + DBV + F) significantly suppressed pain responses compared to that of the vehicle group (Veh + Veh + F, ***𝑃<0.001). Epinephrine (1 and 10 ug/kg) was intraperitoneally injected, and this significantly increased formalin-induced pain as compared with the vehicle group during the late phase (^#𝑃<0.05). Pretreatment of epinephrine (10 ug/kg) before DBV (Epi 10 + DBV + F) significantly reversed the antinociceptive effect of DBV as compared to the DBV only treated group during the late phase of the formalin test (^&&𝑃<0.01).