Effects of spaceflight on myosin heavy-chain content, fibre morphology and succinate dehydrogenase activity in rat diaphragm

2004 ◽  
Vol 448 (2) ◽  
pp. 239-247 ◽  
Author(s):  
Ian M. MacLean ◽  
Charles T. Putman ◽  
Gregory Hansen ◽  
Gordon J. Bell ◽  
Karen J. B. Martinuk ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Heavy Chain ◽  
Rat Diaphragm ◽  
Succinate Dehydrogenase Activity ◽  
Fibre Morphology

Myosin heavy chain composition in young and old rat skeletal muscle: effects of endurance exercise

1995 ◽  
Vol 78 (6) ◽  
pp. 2115-2120 ◽  
Author(s):  
V. K. Sullivan ◽  
S. K. Powers ◽  
D. S. Criswell ◽  
N. Tumer ◽  
J. S. Larochelle ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Myosin Heavy Chain ◽  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Endurance Exercise ◽  
Heavy Chain ◽  
Medial Gastrocnemius ◽  
Type I ◽  
Succinate Dehydrogenase Activity

The objective of this study was to determine the effects of age and exercise on the myosin heavy chain (MHC) composition of skeletal muscle. Young (3 mo) and old (22 mo) female specific pathogen-free barrier-reared Fischer 344 rats were randomly assigned to young untrained or young trained and old untrained or old trained groups, respectively. Young trained and old trained animals performed endurance exercise training on a motorized treadmill for 8 wk. Succinate dehydrogenase activity and MHC isoforms were measured in the plantaris (Plan), lateral and medial gastrocnemius (Gast), and soleus (Sol) muscles. In sedentary animals, aging resulted in a decrease (P < 0.05) in type IIb MHC and an increase (P < 0.05) in type IIa MHC in both the Gast and Plan muscles. Also, aging resulted in a small but significant increase (approximately 4%; P < 0.05) in type I MHC in the Sol. Exercise training resulted in significant (P < 0.05) increases in Gast, Plan, and Sol succinate dehydrogenase activity in both young and old animals. Furthermore, exercise training resulted in a decrease (P < 0.05) in the percentage of type IIb MHC and an increase (P < 0.05) in the percentage of type IIa MHC in the Plan in both young and old animals. These data suggest that there is an age-related shift in locomotor muscle MHC isoforms from a faster to a slower isoform.

Regional differences in myosin heavy chain isoforms and enzyme activities of the rat diaphragm

1992 ◽  
Vol 73 (2) ◽  
pp. 506-509 ◽  
Author(s):  
T. Sugiura ◽  
S. Morita ◽  
A. Morimoto ◽  
N. Murakami
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Enzyme Activities ◽  
Regional Differences ◽  
Oxidative Capacity ◽  
Myosin Heavy Chain Isoforms ◽  
Rat Diaphragm ◽  
Succinate Dehydrogenase Activity ◽  
Significant Difference ◽  
Crural Diaphragm

Myosin heavy chain isoforms and enzyme activities were compared between the costal and crural regions of the rat diaphragm. The percentage of heavy chain (HC) IIb in the crural region of the diaphragm was significantly (P less than 0.05) higher than that in the costal region (mean 7.3 vs. 3.0%), and the percentage of HCI was significantly lower in the crural than in the costal diaphragm (22.7 vs. 27.9%). The distributions of HCIIa and HCIId were relatively homogeneous in both regions. Succinate dehydrogenase activity in the costal diaphragm was 21% greater (P less than 0.01) than in the crural diaphragm. In contrast, there was no significant difference in the activity of phosphofructokinase in the crural and costal diaphragms. These results demonstrate that a difference in myosin heavy chain isoforms and oxidative capacity exists between the costal and crural regions of the rat diaphragm.

Interactive effects of emphysema and malnutrition on diaphragm structure and function

1994 ◽  
Vol 77 (2) ◽  
pp. 947-955 ◽  
Author(s):  
M. I. Lewis ◽  
S. A. Monn ◽  
W. Z. Zhan ◽  
G. C. Sieck
Keyword(s):  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Cross Sectional Area ◽  
Interactive Effects ◽  
Type I ◽  
Specific Force ◽  
Type Ii ◽  
Sectional Area ◽  
Succinate Dehydrogenase Activity ◽  
Cross Sectional

Interactive effects of emphysema (EMP) and prolonged nutritional deprivation (ND) on contractile, morphometric, and metabolic properties of hamster diaphragm muscle (DIA) were examined. Six months after induction of EMP (intratracheal elastase), saline-treated controls (CTL) and EMP hamsters of similar body weights were subjected to ND over 6 wk. Isometric contractile and fatigue properties of costal DIA were determined in vitro. DIA fibers were histochemically classified as type I or II, and fiber succinate dehydrogenase activity and cross-sectional area were determined using quantitative microscopic procedures. From histochemical sections, the number of capillaries per fiber (C/F) and per fiber cross-sectional area (C/A) were determined. ND resulted in progressive loss of body weight (ND-CTL, 23.8%; ND-EMP, 28.4%; P = NS). ND did not affect reduction in optimal length (Lo) of DIA fibers in EMP compared with CTL and ND-CTL hamsters. Maximum specific force (i.e., force/unit area) was reduced by approximately 25% in EMP animals compared with CTL. ND did not improve or exacerbate the reduction in specific force with EMP. ND attenuated improved fatigue resistance of DIA in EMP animals. No differences in fiber type proportions were noted among experimental groups. Significant atrophy of type I and II DIA fibers was noted after ND. Atrophy was proportionately greater in type II fibers of ND-EMP when referenced to EMP animals. Thus adaptive hypertrophy of type II DIA fibers in EMP animals was abolished. Fiber succinate dehydrogenase activity was significantly increased in type I and II fibers in EMP DIA. ND did not affect this metabolic adaptation of DIA fibers to persistent loads imposed by EMP.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracellular distribution of succinate dehydrogenase activity in skeletal muscle fibers of geese

1984 ◽  
Vol 62 (2) ◽  
pp. 235-240 ◽  
Author(s):  
H. J. Swatland
Keyword(s):  
Skeletal Muscle ◽  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Adenosine Triphosphatase ◽  
Muscle Fibers ◽  
Fiber Types ◽  
Succinate Dehydrogenase Activity ◽  
Individual Muscle ◽  
Concentric Zone ◽  
Pectoralis Muscles

Samples of iliotibialis anterior and pectoralis muscles were taken from five ganders (Anser domesticus). Serial transverse sections were reacted for succinate dehydrogenase (SDH) and alkali-stable adenosine triphosphatase (ATPase). The distribution of SDH activity within individual muscle fibers was measured with a scanning photometer. In many individual fibers, SDH activity was stronger in the periphery than in the axis. This gradient was steepest (−0.034 ± 0.019 absorbance units per concentric zone of 2 μm diameter measurements) in pectoralis fibers with strong SDH activity. In the pectoralis, radial gradients were correlated with fiber area so that the smallest fibers tended to have the steepest gradients of SDH activity. However, this relationship was reversed in fibers with strong ATPase and weak SDH activity in the iliotibialis anterior, and the largest fibers tended to have the steepest gradients. In all fiber types of both muscles, fibers with greater mean SDH activity tended to have steeper gradients.

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