Influence of acupuncture intensity on analgesic effects in AA rat models

Yi-Xuan Wang; Yu-Hang Liu; Zi-Liang Zhang; Xuan Qiao; Ying-Chen Li; Liu-Jie Ren; Guang-Hong Ding; Wei Yao; Yi Yu

doi:10.3389/fbioe.2024.1502535

Influence of acupuncture intensity on analgesic effects in AA rat models

Front Bioeng Biotechnol. 2024 Dec 11:12:1502535. doi: 10.3389/fbioe.2024.1502535. eCollection 2024.

Authors

Yi-Xuan Wang^{1

2}, Yu-Hang Liu^{1

2}, Zi-Liang Zhang^{1

2}, Xuan Qiao^{1

2}, Ying-Chen Li^{1

2}, Liu-Jie Ren³, Guang-Hong Ding^{1

2}, Wei Yao^{1

2}, Yi Yu⁴

Affiliations

¹ Department of Aeronautics and Astronautics, Fudan University, Shanghai, China.
² Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, Shanghai, China.
³ Eye and ENT Hospital of Fudan University, Shanghai, China.
⁴ College of Medical Instruments, Shanghai University of Medicine and Health Sciences, Shanghai, China.

Abstract

Objective: To investigate the influence of acupuncture lifting-thrusting frequency and amplitude on the analgesic effects, and its correlation with mast cell degranulation.

Methods: Acute adjuvant arthritis (AA) rat models were employed. Robot-arm aided lifting-thrusting acupuncture therapy was conducted with various frequencies (ranging from 0.5 to 4 Hz) and amplitudes (ranging from 0.5 to 2.0 mm). The rats' pain thresholds were measured multiple times before and after the therapy, and the analgesic effects were evaluated using the pain threshold recovery rate (PTRR), a normalized index. The mast cell degranulation rate (MCdR) at the acupoint was calculated, and a correlation analysis between PTRR and MCdR was performed.

Results: Acupuncture therapy partially restored the pain threshold affected by arthritis. The analgesic effects were influenced by stimulus frequency and amplitude, with best outcomes occurring at an intermediate optimal frequency of 1.0 Hz and amplitude of 1.0-1.5 mm. Similarly, the MCdR peaked at the optimal frequency and amplitude.

Conclusion: Our animal experiment suggests that optimal analgesic effects can be achieved with stimulation at an optimal intensity. This intensity-effect correlation appears to originate from mast cell activation rates under different mechanical stimulus.

Keywords: acupuncture intensity; adjuvant arthritis; analgesia; mast cell; robot arm.

Grants and funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. This work was supported by National Natural Science Foundation of China [grant number: 82305416 (YY), 12172092 (WY), 82174488 (G-HD)]. The work was also supported by Shanghai Municipal Science and Technology Commission (grant number 23YF1418300, YY) and University Research Fund of Shanghai University of Medicine and Health Sciences (grant number: SSF-23-04-004, YY).