Effect of Manual Acupuncture-Induced Injury on Rat Skeletal Muscle

Abstract

ABSTRACT

Background:

Muscle injury stimulates normal quiescent resident satellite (stem) cells to re-enter the cell cycle and execute the myogenic program, resulting in muscle fiber regeneration. We hypothesized that part of acupuncture's efficacy is a consequence of needle-induced injury that stimulates satellite cells within muscle tissue.

Objective:

To determine whether manual acupuncture needling on a single point (ST 36) in a rat model can produce focal muscle damage and activate satellite cells.

Design and Setting:

Four male Sprague-Dawley rats were studied in this experiment at a single US academic institution.

Intervention:

The rats were anesthetized and underwent needling at ST 36 in the tibialis anterior (TA) muscle.

Main Outcome Measure:

Assessment of TA muscle damage was determined using light microscopy. Immunofluorescence was used to detect MyoD antibody, and Western blot to determine MyoD protein.

Results:

Phenotypic and morphological changes associated with focal injury were demonstrated. Injury to the muscle fibers was accompanied by the presence of activated satellite cells at 72 hours following acupuncture, as defined by the increased expression of myogenic regulatory factor MyoD.

Conclusions:

These results suggest that the therapeutic benefits of acupuncture may correlate to the activation of satellite cells due to tissue injury and help to define the mechanisms that underlie the efficacy of acupuncture's clinical application. Prospective studies in diseased tissue and with evaluation at multiple time points are warranted.