Histochemical and mechanical properties of diaphragm muscle in morbidly obese Zucker rats
| Autor: | G. A. Farkas, Luc E. Gosselin, Wen Zhi Zhan, Gary C. Sieck, E. H. Schlenker |
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| Rok vydání: | 1994 |
| Předmět: |
medicine.medical_specialty
Physiology Diaphragm Muscle Fibers Skeletal Contractility Physiology (medical) Internal medicine Respiratory muscle Animals Medicine Respiratory system Specific force biology business.industry Succinate dehydrogenase Metabolism musculoskeletal system Obesity Morbid Rats Rats Zucker Diaphragm (structural system) Succinate Dehydrogenase Microscopy Electron Endocrinology biology.protein Female business Trapezius muscle Muscle Contraction |
| Zdroj: | Journal of Applied Physiology. 77:2250-2259 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/jappl.1994.77.5.2250 |
| Popis: | The purpose of the present study was to evaluate the effects of chronic mass loading produced by obesity on the structural and functional characteristics of the diaphragm in lean and obese Zucker rats. The trapezius muscle served as an internal control. The studies were carried out on 17 lean (303 +/- 24 g) and 16 obese (698 +/- 79 g) Zucker rats. We observed that the diaphragms from obese animals were restructured such that the overall contribution of type I and IIa fibers was significantly increased. As a consequence of this remodeling, overall diaphragm thickness was selectively greater in obese animals. In small isolated diaphragm bundles studied in vitro, we also detected a reduction in specific force in obese animals that was not detected in the trapezius muscle. In vitro fatigue resistance, assessed by repeated stimulation, was similar in muscles of lean and obese animals. Diaphragm fiber oxidative capacity (succinate dehydrogenase activity) was also comparable in lean and obese animals. We conclude that in obesity the diaphragm undergoes modest remodeling that may be beneficial in enhancing force generation. |
| Databáze: | OpenAIRE |
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