Abstract |
The purpose of this study was to examine the interactive effects of unilateral denervation (DN) and prolonged malnutrition (MN) on the structure and function of the diaphragm muscle ( Dia). Four groups of rats were studied: control (Con), MN, DN, and DN-MN. MN began 2 wk after DN and lasted 4 wk. In both the DN and DN-MN groups, the relative loss in Dia weight exceeded the relative change in body weight. Compared with the Con group, Dia specific force was reduced by approximately 40% in both the DN and DN-MN groups but was unaffected in the MN group. Dia fatigue resistance improved in all experimental groups but to a greater extent in the DN and DN-MN groups. In both the DN and DN-MN groups, approximately 50% of Dia fibers were classified as type IIc, whereas fiber type proportions did not change in the MN group. In the DN group, only type IIb/x fibers atrophied, whereas all fiber types atrophied in the MN and DN-MN groups. We conclude that in the DN-MN group the reduction in specific force combined with the reduction in total cross-sectional area of the muscle significantly curtails Dia force-generating capacity.
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Authors | M I Lewis, T J Lorusso, W Z Zhan, G C Sieck |
Journal | Journal of applied physiology (Bethesda, Md. : 1985)
(J Appl Physiol (1985))
Vol. 81
Issue 5
Pg. 2165-72
(Nov 1996)
ISSN: 8750-7587 [Print] United States |
PMID | 8941542
(Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)
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Topics |
- Animal Nutritional Physiological Phenomena
- Animals
- Diaphragm
(innervation, physiology, physiopathology)
- Isometric Contraction
(physiology)
- Male
- Muscle Denervation
- Muscle Fatigue
(physiology)
- Muscle Fibers, Skeletal
(physiology)
- Muscle Relaxation
(physiology)
- Nutrition Disorders
(physiopathology)
- Organ Size
(physiology)
- Rats
- Rats, Sprague-Dawley
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