2. Academic Validation
  3. Referred Somatic Hyperalgesia Mediates Cardiac Regulation by the Activation of Sympathetic Nerves in a Rat Model of Myocardial Ischemia

Referred Somatic Hyperalgesia Mediates Cardiac Regulation by the Activation of Sympathetic Nerves in a Rat Model of Myocardial Ischemia

  • Neurosci Bull. 2022 Apr;38(4):386-402. doi: 10.1007/s12264-022-00841-w.
Xiang Cui 1,  Guang Sun 1 2,  Honglei Cao 3,  Qun Liu 4,  Kun Liu 1,  Shuya Wang 1,  Bing Zhu 5,  Xinyan Gao 6
Affiliations

Affiliations

  • 1 Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
  • 2 Research Center of Traditional Chinese Medicine, The Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, Jilin, 130021, China.
  • 3 Department of Cardiology, Jining No. 1 People's Hospital, Jining, 272100, Shandong, China.
  • 4 Department of Needling Manipulation, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
  • 5 Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China. zhubing@mail.cintcm.ac.cn.
  • 6 Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China. xinyangao2001@msn.com.
PMID: 35471719 DOI: 10.1007/s12264-022-00841-w
Abstract

Myocardial ischemia (MI) causes somatic referred pain and sympathetic hyperactivity, and the role of sensory inputs from referred areas in cardiac function and sympathetic hyperactivity remain unclear. Here, in a rat model, we showed that MI not only led to referred mechanical hypersensitivity on the forelimbs and upper back, but also elicited sympathetic sprouting in the skin of the referred area and C8-T6 dorsal root ganglia, and increased cardiac sympathetic tone, indicating sympathetic-sensory coupling. Moreover, intensifying referred hyperalgesic inputs with noxious mechanical, thermal, and electro-stimulation (ES) of the forearm augmented sympathetic hyperactivity and regulated cardiac function, whereas deafferentation of the left brachial plexus diminished sympathoexcitation. Intradermal injection of the α2 adrenoceptor (α2AR) antagonist yohimbine and agonist dexmedetomidine in the forearm attenuated the cardiac adjustment by ES. Overall, these findings suggest that sensory inputs from the referred pain area contribute to cardiac functional adjustment via peripheral α2AR-mediated sympathetic-sensory coupling.

Keywords

Cardioprotection; Neuromodulation; Referred pain; Sympathetic-sensory coupling; α2 adrenoceptor.

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