New mouse model of skeletal muscle atrophy using spiral wire immobilization.

INTRODUCTION: Disuse-induced skeletal muscle atrophy is a serious concern; however, there is not an effective mouse model to elucidate the molecular mechanisms. We developed a noninvasive atrophy model in mice. METHODS: After the ankle joints of mice were bandaged into a bilateral plantar flexed position, either bilateral or unilateral hindlimbs were immobilized by wrapping in bonsai steel wire. RESULTS: After 3, 5, or 10 days of immobilization of the hip, knee, and ankle, the weight of the soleus and plantaris muscles decreased significantly in both bilateral and unilateral immobilization. MAFbx/atrogin-1 and MuRF1 mRNA was found to have significantly increased in both muscles, consistent with disuse-induced atrophy. Notably, the procedure did not result in either edema or necrosis in the fixed hindlimbs. CONCLUSIONS: This method allows repeated, direct access to the immobilized muscle, making it a useful procedure for concurrent application and assessment of various therapeutic interventions. Muscle Nerve 54: 788-791, 2016.

Acupuncture ameliorated skeletal muscle atrophy induced by hindlimb suspension in mice.

Preventing skeletal muscle atrophy is critical for maintaining quality of life, but it is often a challenging goal for the elderly and patients with severe conditions. We hypothesized that acupuncture in place of exercise training is an alternative non-pharmacological intervention that can help to prevent muscle atrophy. To elucidate the effects of acupuncture on skeletal muscle atrophy caused by hindlimb suspension (HS), we performed acupuncture on mice according to two different methods: acupuncture with electrical stimulation (EA: electroacupuncture) and without electrical stimulation (MA: manual acupuncture). A needle was retained in the gastrocnemius muscle for 30 min every day for 2 weeks in the EA and MA groups. In the EA group, 30 min of repetitive electrical stimulation (1 Hz, 1 ms pulse width, 6.5 mA intensity) was also applied. HS significantly reduced muscle mass and the cross-sectional area of the soleus muscles. This HS-induced reduction was significantly improved in the EA group, although the level of improvement remained insufficient when compared with the control group. We found that the mRNA expression levels of atrogin-1 and MuRF1, which play a principal role in muscle-specific degradation as E3 ubiquitin ligases, were significantly increased in the HS group compared to the control group. EA and MA reduced the HS-induced upregulation of atrogin-1 (p<0.01 in EA and MA) and MuRF1 (p<0.01 in EA) mRNAs. We also found that the expression levels of PI3K, Akt1, TRPV4, adenosine A1 receptor, myostatin, and SIRT1 mRNAs tended to be increased by HS. EA and MA further increased the HS-induced upregulation of Akt1 (p<0.05 in MA) and TRPV4 (p<0.05 in MA) mRNAs. We concluded that acupuncture partially prevented skeletal muscle atrophy. This effect might be due to an increase in protein synthesis and a decrease in protein degradation.

Effect of acupuncture on salivary immunoglobulin A after a bout of intense exercise.

UNLABELLED: In the field of athletics, acupuncture has been used for treatment of injury, reduction of fatigue and management of physical condition. However, there is little information on the effect of acupuncture on the immune function in response to exercise. PURPOSE: The aim of this study was to examine the effect of acupuncture treatment on the mucosal immune function after a single period of intense exercise by measuring salivary immunoglobulin A (SIgA). METHODS: 12 healthy men (23.6+/-SEv 0.3 years) participated in this study with a crossover design. The subjects exercised on a bicycle equipped with an ergometer at 75% VO(2)max for 60 min. Acupuncture treatment was applied at LU6, LI4, ST36 and ST6, for 30 min after the exercise. The control treatment was rest without acupuncture and that the order of the treatment was randomised. We measured parameters including saliva flow rate, SIgA concentration, SIgA secretion rate, heart rate and plasma catecholamine concentration all before the exercise and at 1 h, 2 h, 3 h, 4 h and 24 h after the exercise. The visual analogue scale for self-perceived tiredness and the profile of mood states questionnaires were recorded before the exercise and at 24 h after the exercise. RESULT: Intense exercise-induced decrease of SIgA levels was attenuated by the acupuncture treatment. In contrast, the subjective fatigue score and psychological measurement were not affected by the acupuncture. CONCLUSION: Acupuncture treatment may attenuate the decrease in SIgA level induced by intense exercise.