1987 Fiscal Year Final Research Report Summary
Experimental studies concerning the effects of sympathetic nerve activity on muscular contracting performance
| Project/Area Number |
61580121
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
体育学
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| Research Institution | Toyota Technological Institute |
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Principal Investigator |
SAITO MITSURU Toyota Technological Institute, 工学部, 助教授 (80126862)
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| Co-Investigator(Kenkyū-buntansha) |
NONAKA SIGEHIKO Toyota Technological Institute, 工学部, 助教授 (30023245)
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| Project Period (FY) |
1986 – 1987
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| Keywords | muscle sympathetic nerve activity / microneutography / static and dynamic muscle contraction / percived exertion / 律動的筋収縮 / 疲労感覚 / 主観的運動強度 / 抗疲労作用 |
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| Research Abstract |
The purpose of this study was to investigate the eddects of sympathetic nervous system on exercise performance. Muscle sympathetic nerve activity (MSNA) was recorded using a tungsten microelectrode from rthe tibial nerve at politeal fossa without anaethesia, and was represented quantitatively as the number og burst discharges per one minute (burst rate: BR). Static and rhythmic handgrip exercises as volumntary muscle contractions were performed using an electrodynamometer and a hanfergometer.
Results: (1) Respondse in MSNA to static handgrip at various tensions: Muscle sysmpathnetic nerve activity incrteased fduring static handgrip exerise for two minutes as compared to the resting value and incteased more during higher tension of handgrip. (2) Relationship berwrrn rate in muscle fatigue sensation (RMFS) and sympathetic nerve responese in static and thythmic handgrip exercises: During exhaustive muscle contractions, MSNA-BR inctresed during both the static and dynamic hendgrip as compar
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ed to the values before the exercise, which increased more in parallel with the contracting time. Also RMFS enhanced gradually until the exhaustion in the two modes of handgrip. There was significant corrtelation between RMFS and MSNA-BR during static and rhythmic handgrips. (3) Relationship between calf blood flow and MSNA during sustained handgrip: Calf blood blow datermined by vemous occlusion plethysmography dectreased during handgrip. at the same time, contrarily, MSNA recorded from the same leg increased. Threr was significant correlation between the calf blood flow and MSNA-BR.
Conclusions: First, it is suggested that MSNA is activeted not only by afferent nerve impulses from the active muscle byt by descending nerve impulses from the motor center. Second, the increase in sympathetic outflow to the resting muscles may play an importnat role in elevating the perfusion pressure to the active muscles to compensate for the increased intreamuscular pressure due to contracion. Third, the significant correlation between MSNA-BR and RMFS may indicate a possibility of anti-fatigue action of MSNA poointed out by orbeli in 1923 Less
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