Fig. 1.

Metformin treatment attenuates incision-induced mechanical hypersensitivity and blocks hyperalgesic priming in male mice: (A–C). Metformin treatment starting immediately after baseline measurements, which were done 3 days before plantar incision, decreased mechanical hypersensitivity after plantar incision surgery and prevented plantar incision-induced hyperalgesic priming precipitated by PGE₂ injection. (D–F) In female mice, metformin treatment did not decrease mechanical hypersensitivity compared with vehicle-treated mice. Metformin also failed to prevent plantar incision–induced hyperalgesic priming precipitated by PGE₂ injection. ***P < 0.001; treatment effect; n = 6 for the metformin groups and n = 5 for the vehicle groups.