Feng-Chen Kao - School of Medicine, College of Medicine, I-Shou University, Kaohsiung, Taiwan
Chia-Ming Yen - Department of Anesthesiology, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung ۴۲۷۴۳, Taiwan
Ming-Chia Lin - Department of Nuclear Medicine, E-DA Hospital, College of Medicine, I-Shou University, Kaohsiung ۸۲۴۴۵, Taiwan
Hsien-Yin Liao - College of Chinese Medicine, School of Post-Baccalaureate Chinese Medicine, China Medical University, Taichung ۴۰۴۰۲, Taiwan
Hsin-Cheng Hsu - College of Chinese Medicine, School of Post-Baccalaureate Chinese Medicine, China Medical University, Taichung ۴۰۴۰۲, Taiwan
Yi-Wen Lin - College of Chinese Medicine, Graduate Institute of Acupuncture Science, China Medical University, Taichung ۴۰۴۳۳۲, Taiwan

Objective(s): Chronic pain is considered as pain lasting for more than three months and has emerged as a global health problem affecting individuals and society. Chronic extensive pain is the main syndrome upsetting individuals with fibromyalgia (FM), accompanied by anxiety, obesity, sleep disturbances, and depression, Transient receptor potential vanilloid ۱ (TRPV۱) has been reported to transduce inflammatory and pain signals to the brain.Materials and Methods: Acupoint catgut embedding (ACE) is a novel acupuncture technique that provides continuous effects and convenience. ACE was performed at the bilateral ST۳۶ acupoint. Results: We demonstrated similar pain levels among all groups at baseline. After cold stress, chronic mechanical or thermal nociception was induced (D۱۴: mechanical: ۱.۸۵ ± ۰.۱۳ g; thermal: ۴.۸۵ ± ۰.۲۶ s) and reversed in ACE-treated mice (D۱۴: mechanical: ۳.۹۹ ± ۰.۱۶ g; thermal: ۷.۴۲ ± ۰.۴۵ s) as well as Trpv۱-/- group (Day ۱۴, mechanical: ۴.۲۵ ± ۰.۲ g; thermal: ۷.۹۱ ± ۰.۲۱ s) mice. Inflammatory mediators were augmented in FM individuals and were abridged after ACE management and TRPV۱ gene loss. TRPV۱ and its linked mediators were increased in the thalamus (THA), somatosensory cortex (SSC), medial prefrontal cortex (mPFC), and anterior cingulate cortex (ACC) in FM mice. The up-regulation of these mediators was diminished in ACE and Trpv۱-/- groups. Conclusion: We suggest that chronic pain can be modulated by ACE or Trpv۱-/-. ACE-induced analgesia via TRPV۱ signaling pathways may be beneficial targets for FM treatment.

Acupoint catgut embedding, Chronic pain, Fibromyalgia, Somatosensory cortex, Thalamus TRPV۱