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)

Free autografting of entire limb muscles in the cat: histochemistry and biochemistry

1978 ◽  
Vol 44 (3) ◽  
pp. 431-437 ◽  
Author(s):  
L. C. Maxwell ◽  
J. A. Faulkner ◽  
S. A. Mufti ◽  
A. M. Turowski
Keyword(s):  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Muscle Fibers ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Succinate Dehydrogenase Activity ◽  
Cross Sectional ◽  
The Mean ◽  
Fast Twitch

Fifty extensor digitorium longus muscles of 25 cats were autografted, 33 with and 17 without prior denervation. After 50 days, no significant differences were observed between predenervated and nonpredenervated autografts. Autografted muscles weighed 48% of the weight of control muscles. Few original muscle fibers survived and within 2 wk autografts contained regenerating muscle fibers. The mean cross-sectional area of muscle fibers in the autografts reached 125% of the value for control nontransplanted muscles. The mean percentage of fibers classified high oxidative in autografted muscles was 67% of values for control muscles. SDH activity of autografted muscle homogenates reached 55% of control values. Up to 60 days after surgery autografts had only fast-twitch fibers. At 170 days autografts remained 95% fast twitch in composition. Revascularization began within 4 days, but the capillary to fiber ratio of long term autografts reached only 60% of control values. Although fiber hypertrophy suggests that cats use autografted muscles, lower than control succinate dehydrogenase activity may result from altered recruitment.

scholarly journals Aging reduces succinate dehydrogenase activity in rat type IIx/IIb diaphragm muscle fibers

2020 ◽  
Vol 128 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Matthew J. Fogarty ◽  
Natalia Marin Mathieu ◽  
Carlos B. Mantilla ◽  
Gary C. Sieck
Keyword(s):  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Fiber Type ◽  
Oxidative Capacity ◽  
Diaphragm Muscle ◽  
Type I ◽  
Specific Force ◽  
Succinate Dehydrogenase Activity ◽  
Cross Sectional ◽  
Fresh Frozen

In aged rats, diaphragm muscle (DIAm) reduced specific force and fiber cross-sectional area, sarcopenia, is selective for vulnerable type IIx and/or IIb DIAm fibers, with type I and IIa fibers being resilient. In humans, the oxidative capacity [as measured by maximum succinate dehydrogenase (SDHmax) activity] of fast-type muscle is reduced with aging, with slow-type muscle being unaffected. We hypothesized that in aged Fischer rat DIAm exhibiting sarcopenia, reduced SDHmax activity would occur in type IIx and/or IIb fibers. Rats obtained from the NIA colony (6, 18, and 24 mo old) were euthanized, and ~2-mm-wide DIAm strips were obtained. For SDHmax and fiber type assessments, DIAm strips were stretched (approximately optimal length), fresh frozen in isopentane, and sectioned on a cryostat at 6 μm. SDHmax, quantified by intensity of nitroblue tetrazolium diformazan precipitation, was assessed in a fiber type-specific manner by comparing serial sections labeled with myosin heavy chain (MyHC) antibodies differentiating type I (MyHCSlow), IIa (MyHC2A), and IIx and/or IIb fibers. Isometric DIAm force and fatigue were assessed in DIAm strips by muscle stimulation with supramaximal pulses at a variety of frequencies (5–100 Hz) delivered in 1-s trains. By 24 mo, DIAm sarcopenia was apparent and SDHmax in type IIx and/or IIb fibers activity was reduced ~35% compared with 6-mo-old control DIAm. These results underscore the remarkable fiber type selectivity of type IIx and/or IIb fibers to age-associated perturbations and suggest that reduced mitochondrial oxidative capacity is associated with DIAm sarcopenia. NEW & NOTEWORTHY We examined the oxidative capacity as measured by maximum succinate dehydrogenase activity in older (18 or 24 mo old) Fischer 344 rat diaphragm muscle (DIAm) compared with young rats (6 mo old). In 24-mo-old rats, SDH activity was reduced in type IIx/b DIAm fibers. These SDH changes were concomitant with sarcopenia (reduced specific force and atrophy of type IIx/b DIAm fibers) at 24 mo old. At 18 mo old, there was no change in SDH activity and no evidence of sarcopenia.

Effects of starvation and refeeding on adult male rat diaphragm contractility, fatigue, and fiber types

1993 ◽  
Vol 74 (2) ◽  
pp. 742-749 ◽  
Author(s):  
D. J. Prezant ◽  
D. E. Valentine ◽  
H. H. Kim ◽  
E. I. Gentry
Keyword(s):  
Fatigue Resistance ◽  
Cross Sectional Area ◽  
Male Rats ◽  
Male Rat ◽  
Type I ◽  
Fiber Types ◽  
Type Ii ◽  
Sectional Area ◽  
Cross Sectional ◽  
Type Ii Fibers

The effects of 4.5 days of acute starvation, either alone or followed by refeeding (ad libitum), on diaphragm contractility, fatigue, and fiber types were studied in male rats. Contractility and fatigue resistance indexes were measured in an in vitro costal diaphragm strip preparation with direct stimulation at 37 degrees C. Compared with controls, starvation produced a 28 +/- 1% (P < 0.001) reduction in body weight and an 18 +/- 4% (P < 0.001) reduction in costal diaphragm weight. Twitch and tetanic tensions (normalized for weight or cross-sectional area) were not reduced by starvation. Starvation produced significant increases in fatigue resistance indexes after a 5-Hz stimulation paradigm but not after a 100-Hz paradigm, supporting the hypothesis that fatigue resistance is dependent on the energy demand of a given paradigm. The proportions of type I and type II fibers were similar between diaphragms of starved and control rats, but the cross-sectional area of type II fibers decreased significantly by 18 +/- 7% (P < 0.01). Thus, despite the significant decrease in diaphragm weight after starvation, contractility was preserved and fatigue resistance was increased (low-output paradigm). This is consistent with the decrease in type II fiber area. Refeeding restored all parameters so that there were no longer significant differences in body or diaphragm weight, contractility, fatigue, or fiber types.

The Effects of Non-Weight Bearing on Skeletal Muscle in Older Rats: an Interrupted Bout versus an Uninterrupted Bout

2004 ◽  
Vol 5 (3) ◽  
pp. 195-202 ◽  
Author(s):  
Alissa Guildner Gehrke ◽  
Margaret Sheie Krull ◽  
Robin Shotwell McDonald ◽  
Tracy Sparby ◽  
Jessica Thoele ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Fiber Type ◽  
Weight Bearing ◽  
Cross Sectional Area ◽  
Type I ◽  
Type Ii ◽  
Sectional Area ◽  
Cross Sectional ◽  
Age Related ◽  
Type Ii Fibers

Age-related changes in skeletal muscle, in combination with bed rest, may result in a poorer rehabilitation potential for an elderly patient. The purpose of this study was to determine the effects of non-weight bearing (hind limb unweighting [HU]) on the soleus and extensor digitorum longus (EDL) in older rats. Two non-weight bearing conditions were used: an uninterrupted bout of HU and an interrupted bout of HU. Twenty-one rats were randomly placed into 1 of 3 groups: control, interrupted HU (2 phases of 7 days of HU, separated by a 4-day weight-bearing phase) and an uninterrupted HU (18 uninterrupted days of HU). Following non-weight bearing, the soleus and EDL muscles were removed. Fiber type identification was performed by myofibrillar ATPase and cross-sectional area was determined. The findings suggest that any period of non-weight bearing leads to a decrease in muscle wet weight (19%-45%). Both type I and type II fibers of the soleus showed atrophy (decrease in cross-sectional area, 35%-44%) with an uninterrupted bout of non-weight bearing. Only the type II fibers of the soleus showed recovery with an interrupted bout of weight bearing. In the EDL, type II fibers were more affected by an uninterrupted bout of non-weight bearing (15% decrease in fiber size) compared to the type I fibers. EDL type II fibers showed more atrophy with interrupted bouts of non-weight bearing than with a single bout (a 40% compared to a 15% decrease). This study shows that initial weight bearing after an episode of non-weight bearing may be damaging to type II fibers of the EDL.

Myonuclear number and myosin heavy chain expression in rat soleus single muscle fibers after spaceflight

1996 ◽  
Vol 81 (1) ◽  
pp. 145-151 ◽  
Author(s):  
D. L. Allen ◽  
W. Yasui ◽  
T. Tanaka ◽  
Y. Ohira ◽  
S. Nagaoka ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Soleus Muscle ◽  
Heavy Chain ◽  
Muscle Fibers ◽  
Cross Sectional Area ◽  
Type I ◽  
Type Ii ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fiber Size

The effects of 14 days of spaceflight on myonuclear number, fiber size, and myosin heavy chain (MHC) expression in isolated rat soleus muscle fiber segments were studied. Single soleus muscle fibers from rats flown on the Spacelab Life Sciences-2 14-day mission were compared with those from age-matched ground-based control rats by using confocal microscopy and gel electrophoresis. Spaceflight resulted in a significant reduction in the number of fibers expressing type I MHC and an increase in the number of fibers expressing type IIx or IIa MHC. Space-flight also resulted in an increase in the percentage of fibers coexpressing more than one MHC and in the reexpression of the neonatal isoform of MHC in some fibers. Fiber cross-sectional area was significantly reduced in pure type I MHC-expressing fibers and in fibers coexpressing type I+II MHC but not in fibers expressing one or more type II MHC in the flight rats. The number of myonuclei per millimeter was significantly reduced in type I MHC-expressing fibers from the flight rats but was not significantly different in type I+II and type II MHC-coexpressing fibers. Fibers expressing neonatal MHC were similar in size to control fibers but had significantly fewer myonuclei per millimeter than flight fibers not expressing neonatal MHC. In type I MHC-expressing fibers, the reduction in fiber cross-sectional area was greater than the reduction in myonuclear number; thus the average cytoplasmic volume per myonucleus was significantly lower in flight than in control fibers. The reduction in both myonuclear number and fiber size of fibers expressing type I MHC after 14 days of spaceflight supports the hypothesis that changes in the number of myonuclei may be a contributing factor to the reduction in fiber size associated with chronic unloading of the musculature.

scholarly journals Administration of a soluble activin type IIB receptor promotes skeletal muscle growth independent of fiber type

2010 ◽  
Vol 109 (3) ◽  
pp. 635-642 ◽  
Author(s):  
Samuel M. Cadena ◽  
Kathleen N. Tomkinson ◽  
Travis E. Monnell ◽  
Matthew S. Spaits ◽  
Ravindra Kumar ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Musculoskeletal Diseases ◽  
Fiber Type ◽  
Cross Sectional Area ◽  
Soluble Form ◽  
Control Group ◽  
Type I ◽  
Type Ii ◽  
Sectional Area ◽  
Cross Sectional

This is the first report that inhibition of negative regulators of skeletal muscle by a soluble form of activin type IIB receptor (ACE-031) increases muscle mass independent of fiber-type expression. This finding is distinct from the effects of selective pharmacological inhibition of myostatin (GDF-8), which predominantly targets type II fibers. In our study 8-wk-old C57BL/6 mice were treated with ACE-031 or vehicle control for 28 days. By the end of treatment, mean body weight of the ACE-031 group was 16% greater than that of the control group, and wet weights of soleus, plantaris, gastrocnemius, and extensor digitorum longus muscles increased by 33, 44, 46 and 26%, respectively ( P < 0.05). Soleus fiber-type distribution was unchanged with ACE-031 administration, and mean fiber cross-sectional area increased by 22 and 28% ( P < 0.05) in type I and II fibers, respectively. In the plantaris, a predominantly type II fiber muscle, mean fiber cross-sectional area increased by 57% with ACE-031 treatment. Analysis of myosin heavy chain (MHC) isoform transcripts by real-time PCR indicated no change in transcript levels in the soleus, but a decline in MHC I and IIa in the plantaris. In contrast, electrophoretic separation of total soleus and plantaris protein indicated that there was no change in the proportion of MHC isoforms in either muscle. Thus these data provide optimism that ACE-031 may be a viable therapeutic in the treatment of musculoskeletal diseases. Future studies should be undertaken to confirm that the observed effects are not age dependent or due to the relatively short study duration.

Diaphragm capillarity and oxidative capacity during postnatal development

1991 ◽  
Vol 70 (1) ◽  
pp. 103-111 ◽  
Author(s):  
G. C. Sieck ◽  
T. S. Cheung ◽  
C. E. Blanco
Keyword(s):  
Postnatal Development ◽  
Fiber Type ◽  
Processing System ◽  
Oxidative Capacity ◽  
Cross Sectional Area ◽  
Type I ◽  
Type Ii ◽  
Sectional Area ◽  
Cross Sectional ◽  
Type Ii Fibers

In the cat diaphragm, fiber capillarity, cross-sectional area, and succinate dehydrogenase (SDH) activity were measured across the first 6 wk of postnatal development. Fibers were classified as type I, IIa, IIb, or IIc on the basis of staining for myofibrillar adenosinetriphosphatase (ATPase). Capillaries were identified in sections stained for ATPase at pH 4.2. Fiber cross-sectional areas and SDH activities were quantified using an image-processing system. During postnatal development, the proportions of type I fibers increased while type II fibers decreased. At birth, all type II fibers were IIc. From the 1st to the 2nd postnatal wk, the proportion of type IIc fibers decreased while the numbers of IIa and IIb increased. Thereafter the proportion of type IIb fibers continued to increase while the number of IIa steadily declined. At birth, capillarity, cross-sectional areas, and SDH activities of type I and II fibers were low compared with other postnatal age groups. Fiber cross-sectional areas increased progressively with age. The number of capillaries surrounding type I and II fibers increased markedly by the 2nd wk and then continued to increase at a slower rate. The number of capillaries per fiber area reached a peak by the 2nd wk and then declined as fiber cross-sectional area increased. Postnatal changes in capillarity depended on fiber type, being greatest in IIb. SDH activities of type I and II fibers were initially low during the first 2 postnatal wk and then peaked by the 3rd wk. After the 6th wk, fiber SDH activities decreased to adult values. Among the type II fibers, IIb showed the greatest change in SDH activity during early postnatal development.

Congestive heart failure: differential adaptation of the diaphragm and latissimus dorsi

1995 ◽  
Vol 79 (2) ◽  
pp. 389-397 ◽  
Author(s):  
S. Howell ◽  
J. M. Maarek ◽  
M. Fournier ◽  
K. Sullivan ◽  
W. Z. Zhan ◽  
...  
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Relaxation Time ◽  
Succinate Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Latissimus Dorsi ◽  
Type I ◽  
Succinate Dehydrogenase Activity ◽  
Cross Sectional ◽  
Type I Fibers

Diaphragm and latissimus dorsi muscle functions, histochemistries, and morphometries were studied in anesthetized male Yucatan minipigs with congestive heart failure (CHF) induced by supraventricular tachycardia (n = 5). Sham-operated animals served as a control group (n = 5). In CHF animals, transdiaphragmatic pressure measured during supramaximal phrenic stimulation was reduced by 40% at low frequencies (< or = 20 Hz) and by 60% at higher frequencies. Twitch amplitude and half-relaxation time were also decreased. The cross-sectional areas of type I, IIa, and IIb fibers were reduced in the diaphragm. The proportion of type I fibers increased, whereas type IIa fibers decreased. Succinate dehydrogenase activity was elevated in type IIa and IIb fibers, but diaphragmatic fatigability was not altered. CHF reduced latissimus dorsi isometric force by 40% for stimulation frequencies > or = 30 Hz. The cross-sectional area of latissimus dorsi type IIb fibers was decreased, but twitch characteristics, fiber type composition, succinate dehydrogenase activity, and fatigability were unchanged. Experimental CHF appears to cause greater intrinsic adaptive changes in the diaphragm compared with those in the latissimus dorsi in the minipig. For both muscles, reduced contractile function was associated with atrophy. Impaired performance of the diaphragm may also be attributed to an increase in the relative contribution of type I fibers to the total tension-generating capacity of the muscle and to the pathophysiological mechanisms underlying the shortened relaxation time of the twitch response.

Effects of undernutrition on diaphragm fiber size, SDH activity, and fatigue resistance

1989 ◽  
Vol 66 (5) ◽  
pp. 2196-2205 ◽  
Author(s):  
G. C. Sieck ◽  
M. I. Lewis ◽  
C. E. Blanco
Keyword(s):  
Fatigue Resistance ◽  
Cross Sectional Area ◽  
Type I ◽  
Type Ii ◽  
Sectional Area ◽  
Cross Sectional ◽  
Nutritional Deprivation ◽  
Fiber Atrophy ◽  
Type Ii Fibers ◽  
Diaphragm Fatigue

The influence of prolonged nutritional deprivation on the succinate dehydrogenase (SDH) activity and cross-sectional areas of individual fibers in the rat diaphragm and deep portion of the medial gastrocnemius (MGr) muscles was determined. Fatigue resistance of the diaphragm was measured by means of an in vitro nerve-muscle strip preparation. Fiber SDH activity and cross-sectional area were quantified by means of an image processing system. Diaphragm fatigue resistance was significantly improved in the nutritionally deprived (ND) group. In both muscles, nutritional deprivation resulted in a significant decrease in fiber cross-sectional area (both type I and II), type II fibers showing greater atrophy. The SDH activities of type I and II fibers in the diaphragm were not affected by nutritional deprivation. This contrasted with a significant decrease in the SDH activity of both type I and II fibers in the MGr of ND animals. An assessment of the interrelationships between fiber atrophy and fiber SDH activity revealed a greater effect of malnutrition on those diaphragm type II fibers that had the lowest relative SDH activities and the largest cross-sectional areas. By comparison, the effect of malnutrition on type I and II fibers in the MGr was nonselective with regard to fiber SDH activity. We conclude that the enhanced diaphragm fatigue resistance in the ND animals does not result from an increase in the oxidative capacity of muscle fibers and is best explained by the pattern of diaphragm muscle fiber atrophy.

Effect of Early Low-Intensity Exercise on Rat Hind-Limb Muscles Following Acute Ischemic Stroke

2006 ◽  
Vol 7 (3) ◽  
pp. 163-174 ◽  
Author(s):  
Myoung-Ae Choe ◽  
Gyeong Ju An ◽  
Yoon-Kyong Lee ◽  
Ji Hye Im ◽  
Smi Choi-Kwon ◽  
...  
Keyword(s):  
Hind Limb ◽  
Gastrocnemius Muscle ◽  
Exercise Group ◽  
Cross Sectional Area ◽  
Type I ◽  
Sectional Area ◽  
Muscle Type ◽  
Cross Sectional ◽  
Low Intensity ◽  
Low Intensity Exercise

This study examined the effects of daily low-intensity exercise following acute stroke on mass, Type I and II fiber cross-sectional area, and myofibrillar protein content of hind-limb muscles in a rat model. Adult male Sprague-Dawley rats were randomly assigned to 1 of 4 groups (n = 7-9 per group): stroke (occlusion of the right middle cerebral artery [RMCA]), control (sham RMCA procedure), exercise, and stroke-exercise. Beginning 48 hours post-stroke induction/sham operation, rats in the exercise group had 6 sessions of exercise in which they ran on a treadmill at grade 10 for 20 min/day at 10 m/min. At 8 days poststroke, all rats were anesthetized and soleus, plantaris, and gastrocnemius muscles were dissected from both the affected and unaffected sides. After 6 sessions of exercise following acute ischemic stroke, the stroke-exercise group showed the following significant (p < .05) increases compared to the stroke-only group: body weight and dietary intake, muscle weight of affected soleus and both affected and unaffected gastrocnemius muscle, Type I fiber cross-sectional area of affected soleus and both affected and unaffected gastrocnemius muscle, Type II fiber cross-sectional area of the unaffected soleus, both affected and unaffected plantaris and gastrocnemius muscle, Type II fiber distribution of affected gastrocnemius muscle, and myofibrillar protein content of both affected and unaffected soleus muscle. Daily low-intensity exercise following acute stroke attenuates hind-limb muscle atrophy in both affected and unaffected sides. The effects of exercise are more pronounced in the soleus and gastrocnemius as compared to the plantaris muscle.

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