Novel myosin isoform in nuclear chain fibers of rat muscle spindles produced in response to endurance swimming
| Autor: | Chie Fujitsuka, Atsushi Yoshimura, N Ozawa, Noriaki Fujitsuka, H Ojala, K. Kawakami |
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| Rok vydání: | 1992 |
| Předmět: |
Male
Gene isoform Physiology Myosin ATPase ATPase Fluorescent Antibody Technique Myosins Biology Extensor digitorum muscle chemistry.chemical_compound Oxygen Consumption Isomerism Physical Conditioning Animal Physiology (medical) Myosin Animals Rats Wistar Swimming Adenosine Triphosphatases Soleus muscle Staining and Labeling Glycogen Muscle fatigue Muscles Immunohistochemistry Molecular biology Rats Biochemistry chemistry Body Composition biology.protein |
| Zdroj: | Journal of Applied Physiology. 73:1925-1931 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/jappl.1992.73.5.1925 |
| Popis: | With the use of myosin adenosinetriphosphatase (ATPase) and immunofluorescence staining methods, the adaptive responses of intrafusal and extrafusal fibers to endurance swimming were studied in frozen sections of rat soleus (SOL) and extensor digitorum longus (EDL) muscles. Glycogen depletion confirmed muscle fatigue at the end of a standardized bout of exercise. No significant age-dependent changes in myosin isoforms were detected in any fibers. The 12-wk training increased type I fibers by 10.9% in the SOL and type IIa fibers in the EDL by 16.6%. In trained muscle sections, both staining methods identified a permuted chain fiber, expressed the same as the myosin isoform in the bag2 fiber. However, no exercise-induced change of myosin isoform profile was found in the bag1 and bag2 fibers. Myosin ATPase (and immunofluorescence) staining showed the percentage of permuted chain fibers increased from 0 to 6.7% (5.6%) after 6 wk of training and to 19.2% (14.1%) after 12 wk of training and that it was still at 6.1% (4.2%) 10 wks after training. A novel myosin isoform may thus be expressed in nuclear chain fibers by repetitive recruitment of muscle spindles. |
| Databáze: | OpenAIRE |
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