Toshikazu Miyamoto

Changes in magnetic resonance images in human skeletal muscle after eccentric exercise

To investigate the time-course of changes in transverse relaxation time (T2) and cross-sectional area (CSA) of the quadriceps muscle after a single session of eccentric exercise, magnetic resonance imaging was performed on six healthy male volunteers before and at 0, 7, 15, 20, 30 and 60 min and 12, 24, 36, 48, 72 and 168 h after exercise. Although there was almost no muscle soreness immediately after exercise, it started to increase 1 day after, peaking 1–2 days after the exercise (P<0.01). Immediately after exercise, T2 increased significantly in the rectus femoris, vastus lateralis and intermedius muscles (P<0.05) and decreased quickly continuing until 60 min after exercise. At and after the 12th h, a significant increase was perceived again in the T2 values of the vastus lateralis and intermedius muscles (P<0.01) [maximum 9.3 (SEM 2.8)% and 10.9 (SEM 2.2)%, respectively]. The maximal values were exhibited at 24–36 h after exercise. In contrast, the rectus femoris muscle showed no delayed-stage increase. Also, in CSA, an increase after 12 h was observed in addition to the one immediately after exercise in the vastus lateralis, intermedius and medialis and quadriceps muscles as a whole (P < 0.01), reaching the maximal values at 12–24 h after exercise. The plasma creative kinase activity remained unchanged up to 24 h after and then increased significantly 48 h after exercise (P < 0.05). Beginning 12 h after exercise, the subjects whose T2 and CSA increased less than the others displayed a faster decrease in muscle soreness. These results suggested that T2 and CSA displayed bimodal responses after eccentric exercise and the time-courses of changes in them were similar to those in muscle soreness.

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

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% VO2max 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.

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

Evidence in Safety Issue of Acupuncture (1)

鍼灸臨床で行われている安全性に関する知識や手順には、科学的根拠に乏しい逸話や思い込みも含まれている。鍼灸の安全性を向上させるためには、エビデンスがどれくらい蓄積しているかを整理し、吟味し、活用することが重要である。全日本鍼灸学会研究部安全性委員会では、現在までに報告されている鍼灸の安全管理に関連する研究成果をレビューする作業を開始した。2004年度に取り上げたテーマは次のとおりである : 1. 鍼灸学校における安全性教育と損害賠償の現状2. 手洗いと手指消毒法3. 施術野の消毒法4. 刺鍼から抜鍼までの操作5. 安全な刺鍼深度6. 施術環境の衛生この作業で明らかになった知識や疑問が、学校教育、日常臨床、マニュアル作成、および研究に反映されることを望んでいる。

Influence on Individual Finger Stalls in Pain during Acupuncture Operation

【目的】刺鍼手技中に生じる被験者の痛みの感覚を中心とした評価を行い、指サック使用時の刺鍼操作性を検討した。【デザイン】被験者と施術者をブラインド化させた無作為化比較試験。【方法】16人の施術者と被験者を対象とし、施術者は被験者の腰部に左右各1本刺鍼した後、低周波鍼通電を行った。この実験は指サック非使用時と使用時でそれぞれ行い、実験の順序はランダム化した。被験者には刺鍼操作時や鍼通電時の痛みの程度と質について質問紙に回答させた。施術時間についても計測した。施術者には指サック使用によって感じる施術上の不便さについて調査を行った。【結果】大多数の施術者は指サックを使用しての鍼施術に不便さを訴えた。痛みの程度は指サック非使用時と使用時で統計学的な差は認められなかったが、使用時に高値を示す傾向が見られた。痛みの質は指サック非使用時と使用時で統計学的な差は認められなかったが一部の項目については、指サックの非使用時と使用時との間で選択された数に違いが認められた。被験者は指サックの使用・非使用を識別できなかった。指サック非使用時と使用時で施術時間に有意な差は生じなかった。【結論】指サック使用は刺鍼時の痛み・操作時間に影響を及ぼさない。被験者は刺鍼操作時の指サック使用・非使用を識別できない。