2002 Fiscal Year Final Research Report Summary
STUDIES ON FUNCTIONAL AND MORPHOLOGICAL CHANGES OF MECHANORECEPTOR IN ATROPHIC MUSCLE AFTER PASSIVE MOTION
| Project/Area Number |
12832064
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Institution | SUZUKA UNIVERSITY OF MEDICAL SCIENCE (2002)
Kibi International University (2000-2001) |
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Principal Investigator |
FUJINO Hidemi SUZUKA UNIVERSITY OF MEDICAL SCIENCE, PHYSICAL THERAPY, ASSOCIATE PROFESSOR, 保健衛生学部, 助教授 (20278998)
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| Co-Investigator(Kenkyū-buntansha) |
AKIYAMA Junichi KIBI INTERNATIONAL UNIVERSITY, LECTURER, 保健科学部, 講師 (00309600)
NEYA Toshiaki KIBI INTERNATIONAL UNIVERSITY, PROFESSOR, 保健科学部, 教授 (60032885)
TAKEDA Isao SUZUKA UNIVERSITY OF MEDICAL SCIENCE, PROFESSOR, 保健衛生学部, 教授 (00163402)
OKITA Minoru NAGASAKI UNIVERSITY, ASSISTANT, 医学部, 助手 (50244091)
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| Project Period (FY) |
2000 – 2002
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| Keywords | MUSCLE MECHANORECEPTOR / MUSCLE ATROPHY / PASSIVE MOTION / SOLEUS MUSCLE / ANKLE JOINT / MUSCLE SPINDLE / RAT / FUNCTION |
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| Research Abstract |
The aim of the present study was to examine the responsiveness of skeletal muscle mechanoreceptors in atrophic muscle. The changes in mechanoreceptor activities during stimulation by ramp and hold stretching were studied in the rat soleus muscle with disuse atrophy. Ramp and hold stretching of the muscle was induced by passive motion of the ankle joint. Muscular atrophy was induced by hindlimb suspension or by immobilization with plaster cast at muscle shortening position for two weeks. The suspension and the immobilization resulted in a significant reduction of muscle weight (p<0.05). During the ramp stretching, the discharge frequency of the mechanoreceptors in healthy muscle showed a linear function. Similarly, the mechanoreceptor activities in the suspended hindlimb showed a linear function, but the discharge frequency rate became incrementally higher than in the healthy limb. In the immobilized hindlimb, the discharge frequency of the mechanoreceptors showed an exponential function. During hold stretching, the dynamic component of spindle afferent responses reduced significantly in the suspended and the immobilized hindlimbs. However, mechanoreceptor afferent responses were improved in these muscles after passive motion. These results indicate that following muscular atrophy achieved through two weeks of hindlimb immobilization, the function of the mechanoreceptors in skeletal muscle was changed. We suggest that awareness of changes of proprioceptive sensibility could provide a useful clue for advancing various therapeutic programs for rehabilitation of patients with atrophic muscles.
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