Objective The purpose of this study was to determine how calcitonin gene related peptide (CGRP) via axon reflex participates in increasing local muscle blood flow (MBF) following manual acupuncture (MA). Methods Male Sprague-Dawley rats (N=56, 270-350 g) were used. We examined (1) the effects of MA on MBF in the tibialis anterior (TA) muscle in normal rats; (2) the effects of MA on MBF in the TA injected with saline or hCGRP (low: 2×10 −4 mol/litre; high: 2×10 −3 mol/litre), a competitive CGRP receptor antagonist, in rats; and (3) the effects of MA on MBF in the TA in capsaicin-treated rats. The capsaicin-treated rats were injected with capsaicin dissolved in an ethanol solution within 24 h after birth (50 mg/ kg subcutaneously). MA was applied to the right TA for 1 min. 51Cr-labelled microspheres (15 μm in diameter) were used to measure MBF. Results MA significantly increased MBF without changing arterial blood pressure in normal rats ( p<0.05). MA also significantly increased MBF in saline-injected, low hCGRP 8-37 -injected and high hCGRP 8-37 -injected rats ( p<0.001, 005 and 0.05, respectively). The increases in low and high hCGRP 8-37 -injected rats were lower than those in saline-injected rats, but the difference was not significant. However, MA did not significantly increase MBF in capsaicin-treated rats ( p=0.38). Conclusions We obtained conflicting results, suggesting that the participation of CGRP released via axon reflex may be limited to a local increase in MBF following MA.

The results suggest that adenosine leads to an increase in MBF caused by MA. Adenosine may play a role in acupuncture analgesia by washing out algesic substances. Further studies are needed in order to elucidate the precise mechanism.

We investigated the quantitative relation between soft tissue stiffness palpated from the body surface and hemodynamics in the human forearm. We examined the relation between pressures and blood flow in both the main artery and vein measured by magnetic resonance imaging (MRI), the cross-sectional area of forearm measured by MRI and soft tissue stiffness. Six male volunteers participated. Two tourniquet pressures, 120 mmHg and 230 mmHg, were used to induce an occlusion of the proximal portion of the upper arm. Measurements were made at the mid-belly of the brachioradial muscle. The venous outflow ceased at tourniquet pressures of 120 and 230 mmHg. The arterial flow was interrupted at 230 mmHg. Larger increases of the cross-sectional area and soft tissue stiffness were found at 120 mmHg than at 230 mmHg. The increase of the cross-sectional area of muscle was larger than that of the surrounding connective tissue during occlusion. We propose that low-pressure compression occludes venous outflow without restricting arterial inflow and induces an increase of the cross-sectional area that reflects the intramuscular pressure; and changes in this pressure caused by fluid accumulation should be the major factor for change in stiffness.

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Objective: It is very important that oxidative stress is estimated for us to understand a player's condition in the field of sports. The purpose of this study was to investigate whether electroacupuncture has an effect on exercise-induced oxidative stress. Methods: Ten healthy male volunteers participated in both the electroacupuncture (EA) group and the control group in a crossover design. EA at a frequency of 2 Hz and optimum intensity was performed in the subjects for 10 minutes in both the medial vastus muscles. During ergometer exercise by ramp load, respiratory metabolism including the RC point was recorded as the indication of energy metabolism. Blood was collected from the fingertips of the subjects, and then their levels of oxidative stress (d-ROMs test) and antioxidative (BAP test) were determined by using a Free Radical Analytical System (FRAS 4, Wismell Instruments). Six measurements were taken; at rest, immediately after EA and following exercise, and at 20, 40, and 60 minutes following exercise. Results: The RC point was significantly prolonged in the EA group compared with the control group. The level of oxidative stress (d-ROMs test) in the control group increased significantly at 20 minutes following exercise compared with rest (before exercise) and this increase was sustained until 60 minutes after exercise. In contrast, it did not significantly change in the EA group. Whereas the antioxidative level (BAP test) in the EA group significantly increased immediately following exercise compared with rest (before exercise), it did not increase in the control group. Conclusion: These results suggest that electroacupuncture might enhance the antioxidative level (BAP test) and inhibit the level of oxidative stress (d-ROMs test) by effecting a change in respiratory metabolism. We propose that electroacupuncture might be useful for sports conditioning.