Effect of acute nutritional deprivation on diaphragm structure and function

1990 ◽  
Vol 68 (5) ◽  
pp. 1938-1944 ◽  
Author(s):  
M. I. Lewis ◽  
G. C. Sieck
Keyword(s):  
Nerve Stimulation ◽  
Muscle Fibers ◽  
Medial Gastrocnemius ◽  
Fatigue Properties ◽  
Muscle Stimulation ◽  
Type I ◽  
Cross Sectional ◽  
Nutritional Deprivation ◽  
Nerve Muscle

The influence of 90 h of acute nutritional deprivation (ND) on the cross-sectional areas of muscle fibers and the contractile and fatigue properties of the adult rat diaphragm were determined. Isometric contractile properties and fatigue resistance of the diaphragm were measured by means of an in vitro nerve-muscle strip preparation. Contractions were evoked by using phrenic nerve stimulation (left hemidiaphragm) or direct muscle stimulation (right hemidiaphragm) in the presence of curare. Acute ND resulted in a 20% reduction in body weight. No significant decrements in diaphragm or soleus weights were noted in the ND animals compared with controls (CTL), whereas the weight of the medial gastrocnemius was reduced by 20% in the ND animals. Peak twitch and tetanic tensions (normalized for the weight of the diaphragm strip) were not reduced in ND compared with CTL animals after either nerve or muscle stimulation. The fatigue index of the diaphragm was significantly reduced in ND animals only after nerve stimulation. After the fatigue test, there was rapid recovery of the additional fatigue noted with nerve stimulation. The proportions of type I and II muscle fibers of the diaphragm were similar in the CTL and ND animals. No differences in diaphragm cross-sectional areas were noted for either type I or II muscle fibers in the CTL and ND animals. It is concluded that acute ND has no effect on diaphragm contractility or morphometry and only an inconsequential influence on diaphragm fatigue.

Adaptations of the diaphragm in emphysema

1992 ◽  
Vol 72 (3) ◽  
pp. 934-943 ◽  
Author(s):  
M. I. Lewis ◽  
W. Z. Zhan ◽  
G. C. Sieck
Keyword(s):  
Muscle Fibers ◽  
Capillary Density ◽  
Histochemical Staining ◽  
Diaphragm Muscle ◽  
Fatigue Properties ◽  
Type I ◽  
Cross Sectional ◽  
Metabolic Properties ◽  
Type Ii Fibers

In adult male hamsters the influence of emphysema (EMP) on the in vitro contractile and fatigue properties and the histochemical, morphometric, and metabolic properties of muscle fibers in the costal diaphragm was determined 6 mo after the administration of either elastase or saline (controls, CTL). Isometric contractile properties were determined in vitro using supramaximal direct muscle stimulation. Optimal fiber length for force generation was significantly shorter in the EMP than in the CTL diaphragm. Maximum specific force (i.e., force per unit area) was 25% lower than CTL. Fatigue resistance was significantly improved in the EMP diaphragm compared with CTL. Diaphragm muscle fibers were classified as type I or II on the basis of histochemical staining for myofibrillar adenosinetriphosphatase after alkaline preincubation. The proportions of type I and II fibers were similar between the two groups. Cross-sectional areas of type II fibers were 30% larger in EMP than in CTL diaphragms. Succinate dehydrogenase activities of both type I and II fibers were higher in EMP than in CTL diaphragms. The number of capillaries surrounding both type I and II fibers increased with EMP, but in proportion to the hypertrophy of these fibers. Thus, capillary density (number of capillaries per fiber cross-sectional area) remained unchanged. We postulate that these contractile, morphometric, and metabolic adaptations reflect an increased activation of the diaphragm in response to the loads imposed by EMP.

Adaptations of diaphragm and medial gastrocnemius muscles to inactivity

1992 ◽  
Vol 72 (4) ◽  
pp. 1445-1453 ◽  
Author(s):  
W. Z. Zhan ◽  
G. C. Sieck
Keyword(s):  
Fiber Type ◽  
Relaxation Times ◽  
Medial Gastrocnemius ◽  
Fatigue Properties ◽  
Type I ◽  
Cross Sectional ◽  
Isometric Twitch ◽  
The Right ◽  
Type I Fibers

The effects of 2 wk of inactivity on in vitro contractile properties of diaphragm and medial gastrocnemius (MG) muscles were examined in adult hamsters. In addition, inactivity effects on fiber-type proportions and cross-sectional areas were studied. Inactivity of the right hemidiaphragm or MG muscle was induced by either tetrodotoxin (TTX) blockade of nerve impulses or denervation (DNV). Inactivity effects on diaphragm or MG were compared with corresponding sham (saline-treated or untreated control) muscles. After both TTX- and DNV-induced inactivity, isometric twitch contraction and half-relaxation times were prolonged, maximum tetanic force decreased, and fatigue resistance improved. Proportions of type I and II fibers in both diaphragm and MG were unaffected by TTX- and DNV-induced inactivity. However, in both muscles, type I fibers hypertrophied, whereas type II fibers atrophied. In diaphragm, contractile and morphometric adaptations after DNV were generally more pronounced than those induced by TTX. In addition, compared with corresponding untreated or saline-treated control groups, inactivity effects (both TTX and DNV) on MG were generally greater than those induced in diaphragm, with the exception of hypertrophy of type I fibers. We conclude that inactivity exerts differential effects on type I and II fibers in both diaphragm and MG. Yet, these morphometric adaptations cannot completely account for the adaptations in muscle contractile and fatigue properties after inactivity.

Diaphragm muscle fatigue resistance during postnatal development

1991 ◽  
Vol 71 (2) ◽  
pp. 458-464 ◽  
Author(s):  
G. C. Sieck ◽  
M. Fournier ◽  
C. E. Blanco
Keyword(s):  
Postnatal Development ◽  
Fatigue Resistance ◽  
Muscle Fibers ◽  
Diaphragm Muscle ◽  
Fatigue Properties ◽  
Type I ◽  
Type Ii ◽  
Cross Sectional ◽  
Type I Fibers ◽  
Type Ii Fibers

postnatal development. Both twitch contraction time and half-relaxation time decreased progressively with age. Correspondingly, the force-frequency curve was shifted to the left early in development compared with adults. The ratio of peak twitch force to maximum tetanic force decreased with age. Fatigue resistance of the diaphragm was highest at birth and then progressively decreased with age. At birth, most diaphragm muscle fibers stained darkly for myofibrillar adenosinetriphosphatase after alkaline preincubation and thus would be classified histochemically as type II. During subsequent postnatal development, the proportion of type I fibers (lightly stained for adenosinetriphosphatase) increased while the number of type II fibers declined. At birth, type I fibers were larger than type II fibers. The size of both fiber types increased with age, but the increase in cross-sectional area was greater for type II fibers. On the basis of fiber type proportions and mean cross-sectional areas, type I fibers contributed 15% of total muscle mass at birth and 25% in adults. Thus postnatal changes in diaphragm contractile and fatigue properties cannot be attributed to changes in the relative contribution of histochemically classified type I and II fibers. However, the possibility that these developmental changes in diaphragm contractile and fatigue properties correlated with the varying contractile protein composition of muscle fibers was discussed.

Effect of corticosteroids on diaphragm fatigue, SDH activity, and muscle fiber size

1992 ◽  
Vol 72 (1) ◽  
pp. 293-301 ◽  
Author(s):  
M. I. Lewis ◽  
S. A. Monn ◽  
G. C. Sieck
Keyword(s):  
Fatigue Resistance ◽  
Muscle Fiber ◽  
Fiber Type ◽  
Processing System ◽  
Medial Gastrocnemius ◽  
Type I ◽  
Type Ii ◽  
Cross Sectional ◽  
Type Ii Fibers

The influence of dexamethasone on diaphragm (DIA) fatigue, oxidative capacity, and fiber cross-sectional areas (CSA) was determined in growing hamsters. One group received dexamethasone by daily subcutaneous injection for 21 days (D animals), while pair-weight (P) and free-eating controls (CTL) received saline subcutaneously. Isometric contractile properties of the DIA were determined in vitro by supramaximal direct muscle stimulation in the presence of curare. DIA fatigue resistance was determined through repetitive stimulation at 40 pulses/s for 2 min. A computer-based image-processing system was used to histochemically determine muscle fiber-type proportions, CSA, and succinate dehydrogenase activities. The medial gastrocnemius muscle (MG) was used as a limb muscle control, with histochemical studies being performed on both the superficial (s) and deep/red (r) portions. Dexamethasone markedly attenuated the normal increment in body weight over the 3-wk period. DIA fatigue resistance was significantly reduced in the D compared with CTL and P animals. Dexamethasone had no effect on fiber-type proportions of the DIA or MGr (MGs contained only type II fibers). In the DIA, the CSA of type II fibers was reduced 33% in D and 18.5% in P animals compared with CTL. Although no significant atrophy was noted in the type I DIA fibers of either D or P animals, a trend toward significance was noted in D animals compared with CTL. In the MGs, the CSA of type II fibers was reduced 33% in D and 16.5% in P animals compared with CTL. Significant atrophy of type I and II fibers of the MGr was noted in D animals compared with CTL (33.8 and 35% reductions, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro human masseter muscle hypersensitivity: a possible explanation for increase in masseter tone

1996 ◽  
Vol 80 (5) ◽  
pp. 1547-1553 ◽  
Author(s):  
P. J. Adnet ◽  
H. Reyford ◽  
B. M. Tavernier ◽  
T. Etchrivi ◽  
I. Krivosic ◽  
...  
Keyword(s):  
Masseter Muscle ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Threshold Concentration ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Cross Sectional ◽  
Significant Difference ◽  
Maximal Tension

To determine whether a difference in fiber-type caffeine and Ca2+ sensitivities exists between human masseter and vastus lateralis skeletal muscle, we compared the fiber-type caffeine sensitivities in chemically skinned muscle fibers from 13 masseter and 18 vastus lateralis muscles. Caffeine sensitivity was defined as the threshold concentration inducing > 10% of the maximal tension obtained after the fiber was loaded with a 1.6 x 10(-2) mM Ca2+ solution for 30 s. Significant difference in the mean caffeine sensitivity was found between type I masseter fibers [2.57 +/- 1.32 (SD) mM] vs. type I (6.02 +/- 1.74 mM) and type II vastus lateralis fibers (11.25 +/- 3.13 mM). Maximal Ca(2+)-activated force per cross-sectional area was significantly different between masseter and vastus lateralis fibers. However, the Ca2+ concentration corresponding to half-maximal tension (pCa50) was not significantly different between type I masseter (pCa50 5.9 +/- 0.02) and type I vastus lateralis muscle (pCa50 6.01 +/- 0.08). These results suggest that the increase in caffeine sensitivity of masseter muscle reflects the presence of a low reactivity threshold of the sarcoplasmic reticulum.

Mechanical stimulation of the plantar foot surface attenuates soleus muscle atrophy induced by hindlimb unloading in rats

2005 ◽  
Vol 99 (2) ◽  
pp. 739-746 ◽  
Author(s):  
Antonios Kyparos ◽  
Daniel L. Feeback ◽  
Charles S. Layne ◽  
Daniel A. Martinez ◽  
Mark S. F. Clarke
Keyword(s):  
Muscle Atrophy ◽  
Soleus Muscle ◽  
Gastrocnemius Muscle ◽  
Hindlimb Unloading ◽  
Medial Gastrocnemius ◽  
Type I ◽  
Cross Sectional ◽  
Plantar Surface ◽  
Male Wistar Rats ◽  
Medial Gastrocnemius Muscle

Unloading-induced muscle atrophy occurs in the aging population, bed-ridden patients, and astronauts. This study was designed to determine whether dynamic foot stimulation (DFS) applied to the plantar surface of the rat foot can serve as a countermeasure to soleus muscle atrophy normally observed in hindlimb unloaded (HU) rats. Forty-four mature (6 mo old), male Wistar rats were randomly assigned to ambulatory control, HU alone, HU with active DFS (i.e., plantar contact with active inflation), HU with passive DFS (i.e., plantar contact without active inflation), and HU while wearing a DFS boot with no plantar contact groups. Application of active DFS during HU significantly counteracted the atrophic response by preventing ∼85% of the reduction in type I myofiber cross-sectional area (CSA) in the soleus while preventing ∼57% of the reduction in type I myofiber CSA and 43% of the reduction in type IIA myofiber CSA of the medial gastrocnemius muscle. Wearing of a DFS boot without active inflation prevented myofiber atrophy in the soleus of HU animals in a fashion similar to that observed in HU animals that wore an actively inflated DFS boot. However, when a DFS boot without plantar surface contact was worn during HU, no significant protection from HU-induced myofiber atrophy was observed. These results illustrate that the application of mechanical foot stimulation to the plantar surface of the rat foot is an effective countermeasure to muscle atrophy induced by HU.

Diaphragm disuse reduces Ca2+uptake capacity of sarcoplasmic reticulum

1997 ◽  
Vol 82 (1) ◽  
pp. 164-171 ◽  
Author(s):  
Sandra Howell ◽  
Wen-Zhi Zhan ◽  
Gary C. Sieck
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Compartmental Analysis ◽  
Fatigue Properties ◽  
Type I ◽  
Uptake Capacity ◽  
Relative Contribution ◽  
Intracellular Compartments ◽  
Muscle Groups ◽  
The Impact

Howell, Sandra, Wen-Zhi Zhan, and Gary C. Sieck.Diaphragm disuse reduces Ca2+uptake capacity of sarcoplasmic reticulum. J. Appl. Physiol. 82(1): 164–171, 1997.—Chronic phrenic tetrodotoxin (TTX) blockade and phrenic denervation (Dnv) of hamster diaphragm result in decreased maximum specific tension, prolonged contraction time, and improved fatigue resistance (W. Z. Zhan and G. C. Sieck. J. Appl. Physiol. 72: 1445–1453, 1992). An underlying increased relative contribution of type I fibers to total muscle mass appears to be consistent with, but does not completely account for, changes in contractile and fatigue properties. The present study was designed to evaluate a potential role for altered cellular Ca2+metabolism in the adaptive response of the diaphragm to chronic disuse. An analytic method based on simulation and modeling of long-term45Ca2+efflux data was used to estimate Ca2+ contents (nmol Ca2+/g wet wt tissue) and exchange fluxes (nmol Ca2+ ⋅ min−1 ⋅ g−1) for extracellular and intracellular compartments in the in vitro hamster hemidiaphragm after prolonged disuse. Three groups were compared: control (Con, n = 5), phrenic TTX blockade (TTX, n = 5), and phrenic denervation (Dnv, n = 5). Experimental muscles were loaded with45Ca2+for 1 h, and efflux data were collected for 8 h by using a flow-through tissue chamber. Compartmental analysis of efflux data estimated that the Ca2+ contents and Ca2+ exchange fluxes of the largest and slowest intracellular compartment (putative longitudinal reticulum) were reduced by ∼50% in TTX and Dnv muscle groups compared with Con. In addition, the kinetic model predicted significant decreases in total intracellular Ca2+ and total diaphragm Ca2+ in TTX and Dnv muscles. We conclude that the data support the hypothesis that the capac- ity of the sarcoplasmic reticulum for Ca2+ sequestration is reduced in chronic diaphragm disuse. The impact of this effect on diaphragm contractile and fatigue properties is discussed.

Effect of Pi on unloaded shortening velocity of slow and fast mammalian muscle fibers

2002 ◽  
Vol 282 (4) ◽  
pp. C647-C653 ◽  
Author(s):  
Jeffrey J. Widrick
Keyword(s):  
Fiber Type ◽  
Muscle Fibers ◽  
Medial Gastrocnemius ◽  
Type I ◽  
Shortening Velocity ◽  
Cross Bridge ◽  
Skinned Muscle ◽  
Specific Effects ◽  
Cross Bridges ◽  
Bridge Models

Chemically skinned muscle fibers, prepared from the rat medial gastrocnemius and soleus, were subjected to four sequential slack tests in Ca2+-activating solutions containing 0, 15, 30, and 0 mM added Pi. Pi (15 and 30 mM) had no effect on the unloaded shortening velocity ( V o) of fibers expressing type IIb myosin heavy chain (MHC). For fibers expressing type I MHC, 15 mM Pi did not alter V o, whereas 30 mM Pireduced V o to 81 ± 1% of the original 0 mM Pi value. This effect was readily reversible when Pi was lowered back to 0 mM. These results are not compatible with current cross-bridge models, developed exclusively from data obtained from fast fibers, in which V o is independent of Pi. The response of the type I fibers at 30 mM Pi is most likely the result of increased internal drag opposing fiber shortening resulting from fiber type-specific effects of Pi on cross bridges, the thin filament, or the rate-limiting step of the cross-bridge cycle.

scholarly journals Morphological and Biochemical Effects on the Skeletal Muscle of Ovariectomized Old Female Rats Submitted to the Intake of Diets with Vegetable or Animal Protein and Resistance Training

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Glaucia Figueiredo Braggion ◽  
Elisabete Ornelas ◽  
Jurema Carmona Sattin Cury ◽  
Natália Edviges Alves Lima ◽  
Rita C. Aquino ◽  
...  
Keyword(s):  
Resistance Training ◽  
Functional Limitations ◽  
The Elderly ◽  
Volume Density ◽  
Female Rats ◽  
Medial Gastrocnemius ◽  
Ovariectomized Rats ◽  
Type I ◽  
Cross Sectional ◽  
Protein Mass

Introduction. Sarcopenia is a process characterized by reduction in protein mass and muscle strength with increasing age, especially in the postmenopausal period, resulting in functional limitations and with great impact on the physical autonomy of the elderly.Objective. To evaluate the effects of diets with vegetable proteins (VP) or animal proteins (AP) associated with resistance training (RT) on the structural and biochemical parameters of the medial gastrocnemius muscle in Wistar rats with sarcopenia.Methods. An experimental model with ovariectomized rats was used to induce sarcopenia and resistance training. The histochemical technique was used for the typing of muscle fibers, the cross-sectional area of myocytes, and volume densities of myocytes and interstitium; the technique of Picrosirius stain was used to highlight the collagen fibers.Results. The VP diet was not able to minimize the effects of sarcopenia in the medial gastrocnemius of sedentary animals and when associated with RT, it promoted maintenance of the CSA, attenuating the atrophy of type IIB fibers in the medial gastrocnemius. The AP diet in sedentary animals protected the type I fibers. When combined with RT, the AP promoted muscle remodeling, with reduction in volume density of type I and IIA fibers, and increase of IIB fibers, together with an increase in collagen volume density.Conclusion. The data suggest a tendency to better results of hypertrophy in animal groups that consumed the AP diet, even the sedentary animals, although more evident in those trained.

scholarly journals Reduced Appendicular Lean Body Mass, Muscle Strength, and Size of Type II Muscle Fibers in Patients with Spondyloarthritis versus Healthy Controls: A Cross-Sectional Study

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Kristine Røren Nordén ◽  
Hanne Dagfinrud ◽  
Amund Løvstad ◽  
Truls Raastad
Keyword(s):  
Body Composition ◽  
Muscle Strength ◽  
Lean Body Mass ◽  
Body Mass ◽  
Muscle Fibers ◽  
Type I ◽  
Healthy Controls ◽  
Type Ii ◽  
Mineral Density ◽  
Cross Sectional

Introduction. The purpose of this study was to investigate body composition, muscle function, and muscle morphology in patients with spondyloarthritis (SpA).Methods. Ten male SpA patients (mean ± SD age39±4.1years) were compared with ten healthy controls matched for sex, age, body mass index, and self-reported level of physical exercise. Body composition was measured by dual energy X-ray absorptiometry. Musculus quadriceps femoris (QF) strength was assessed by maximal isometric contractions prior to test of muscular endurance. Magnetic resonance imaging of QF was used to measure muscle size and calculate specific muscle strength. Percutaneous needle biopsy samples were taken fromm. vastus lateralis.Results. SpA patients presented with significantly lower appendicular lean body mass (LBM) (p=0.02), but there was no difference in bone mineral density, fat mass, or total LBM. Absolute QF strength was significantly lower in SpA patients (p=0.03) with a parallel trend for specific strength (p=0.08). Biopsy samples from the SpA patients revealed significantly smaller cross-sectional area (CSA) of type II muscle fibers (p=0.04), but no difference in CSA type I fibers.Conclusions. Results indicate that the presence of SpA disease is associated with reduced appendicular LBM, muscle strength, and type II fiber CSA.

Sign in / Sign up

Export Citation Format

Share Document