Fig. 7.

Peripheral α₂ARs mediate the cardiac adjustment elicited by electrical stimulation in the skin area with referred mechanical hypersensitivity in MI rats. A Experimental protocol and representative echocardiography images of the left ventricle (LV) before and after drug treatment. B–D LV ejection fraction (B), heart rate (C), and cardiac output (D) in control rats, and in MI rats in response to electrical stimulation (ES, 3 mA, 15 Hz, 30 s), intradermal injection of yohimbine (YOB, 5 µg/20 µL, an α₂AR antagonist) and dexmedetomidine (DEX, 5 µg/20 µL, a potent and selective α₂AR agonist that inhibits norepinephrine release from synaptic vesicles) at the sensitized area (PC6) on the forelimb (n = 8–10/group; *P <0.05, ***P <0.001, vs control; ^#P <0.05, ^###P <0.001, vs MI 7 days; ^&P <0.05, ^&&P <0.01, ^&&&P <0.001, vs MI 7 days+ES). One-way ANOVA with Bonferroni test in B–D.