Glycogen and histological changes in muscle grafts of rats during fasting or exercise

1982 ◽  
Vol 60 (3) ◽  
pp. 387-391 ◽  
Author(s):  
Franz S. F. Mong ◽  
James L. Poland ◽  
Jerry W. Poland
Keyword(s):  
Skeletal Muscle ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Sprague Dawley ◽  
Normal Muscle ◽  
Histological Changes ◽  
Glycogen Concentration ◽  
Sprague Dawley Rats ◽  
Resting Muscle

The metabolic integrity of skeletal muscle grafts must be restored, along with histological regeneration, if muscle transplants are to be clinically acceptable. The purpose of the present study was to contrast glycogen changes in muscle grafts after exercise or fasting with those in normal muscles. The extensor digitorum longus (EDL) and soleus (SOL) muscles were switched to each other's muscle bed in one leg of male Sprague–Dawley rats. Fifty days later, some of the rats were fasted for 48 h and sacrificed either immediately or after 4 h of refeeding. Other rats were run on a treadmill for 30 min (1 mi/h (0.447 m/s)) and sacrificed either immediately or after 4 h of resting. Muscle grafts and contralateral normal muscles of these experimental, as well as control animals (neither exercised nor fasted), were removed for determination of glycogen concentration. The results show that glycogen in muscle grafts, as in normal muscles, decreases with exercise or fasting. After 4 h of rest or refeeding, glycogen is restored in both grafts and normal muscles. It is concluded, therefore, that muscle grafts are metabolically active and that their pattern of utilization and restoration of glycogen in response to physiological events, such as exercise or fasting, is similar to that of normal muscle.

Spaceflight on STS-48 and earth-based unweighting produce similar effects on skeletal muscle of young rats

1993 ◽  
Vol 74 (5) ◽  
pp. 2161-2165 ◽  
Author(s):  
M. E. Tischler ◽  
E. J. Henriksen ◽  
K. A. Munoz ◽  
C. S. Stump ◽  
C. R. Woodman ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Extensor Digitorum Longus ◽  
Space Shuttle ◽  
Weight Bearing ◽  
Similar Rate ◽  
Extensor Digitorum ◽  
Hindlimb Suspension ◽  
Albino Rats ◽  
Sprague Dawley ◽  
Ambient Temperatures

Our knowledge of the effects of unweighting on skeletal muscle of juvenile rapidly growing rats has been obtained entirely by using hindlimb-suspension models. No spaceflight data on juvenile animals are available to validate these models of simulated weightlessness. Therefore, eight 26-day-old female Sprague-Dawley albino rats were exposed to 5.4 days of weightlessness aboard the space shuttle Discovery (mission STS-48, September 1991). An asynchronous ground control experiment mimicked the flight cage condition, ambient shuttle temperatures, and mission duration for a second group of rats. A third group of animals underwent hindlimb suspension for 5.4 days at ambient temperatures. Although all groups consumed food at a similar rate, flight animals gained a greater percentage of body mass per day (P < 0.05). Mass and protein data showed weight-bearing hindlimb muscles were most affected, with atrophy of the soleus and reduced growth of the plantaris and gastrocnemius in both the flight and suspended animals. In contrast, the non-weight-bearing extensor digitorum longus and tibialis anterior muscles grew normally. Earlier suspension studies showed that the soleus develops an increased sensitivity to insulin during unweighting atrophy, particularly for the uptake of 2-[1,2–3H]deoxyglucose. Therefore, this characteristic was studied in isolated muscles within 2 h after cessation of spaceflight or suspension. Insulin increased uptake 2.5- and 2.7-fold in soleus of flight and suspended animals, respectively, whereas it increased only 1.6-fold in control animals. In contrast, the effect of insulin was similar among the three groups for the extensor digitorum longus, which provides a control for potential systemic differences in the animals.

scholarly journals Effect of body temperature during exercise on skeletal muscle cytochrome c oxidase content

2002 ◽  
Vol 93 (2) ◽  
pp. 526-530 ◽  
Author(s):  
Christopher R. Mitchell ◽  
M. Brennan Harris ◽  
Anthony R. Cordaro ◽  
Joseph W. Starnes
Keyword(s):  
Body Temperature ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Sprague Dawley ◽  
Ambient Temperatures ◽  
Sprague Dawley Rats ◽  
Mitochondrial Heat Shock Protein

This study determined the role of body temperature during exercise on cytochrome- c oxidase (CytOx) activity, a marker of mitochondrial content, and mitochondrial heat shock protein 70 (mtHSP70), which is required for import of nuclear-coded preproteins. Male, 10-wk-old, Sprague-Dawley rats exercised identically for 9 wk in ambient temperatures of 23°C ( n = 10), 8°C with wetted fur ( n = 8), and 4°C with wetted fur and fan ( n = 7). These conditions maintained exercising core temperature (Tc) at 40.4, 39.2, or 38.0°C (resting temperature), respectively. During weeks 3–9, exercisers ran 5 days/wk up a 6% grade at 20 m/min for 60 min. Animals were housed at 23°C. Gastrocnemius CytOx activity in Tc=38.0°C (83.5 ± 5.5 μatoms O · min−1 · g wet wt−1) was greater than all other groups ( P< 0.05), exceeding sedentary ( n = 7) by 73.2%. Tc of 40.4 and 39.2°C also were higher than sedentary by 22.4 and 37.4%, respectively ( P < 0.05). Quantification of CytOx content verified that the increased activity was due to an increase in protein content. In extensor digitorum longus, a nonactive muscle, CytOx was not elevated in Tc = 38.0°C. mtHSP70 was significantly elevated in gastrocnemius of Tc = 38.0°C compared with sedentary ( P < 0.05) but was not elevated in extensor digitorum longus ( P > 0.05). The data indicate that decreasing exercise Tc may enhance mitochondrial biogenesis and that mtHSP70 expression is not dependent on temperature.

Adrenalectomy eliminates both fiber-type differences and starvation effects on denervated muscle

1988 ◽  
Vol 255 (6) ◽  
pp. E850-E856 ◽  
Author(s):  
R. R. Almon ◽  
D. C. Dubois
Keyword(s):  
Muscle Mass ◽  
Extensor Digitorum Longus ◽  
Fiber Type ◽  
Sprague Dawley ◽  
Denervated Muscle ◽  
Adrenalectomized Animal ◽  
Sprague Dawley Rats ◽  
Starvation Effects ◽  
The Difference ◽  
Denervated Muscles

This report describes changes in muscle mass of innervated and denervated pairs of muscles taken from intact and adrenalectomized 250-g male Sprague-Dawley rats provided with different diets. Diets ranged from a nutritionally complete liquid diet to starvation (water only). In the intact animals, muscles with a more tonic character (soleus) are less sensitive to starvation than are muscles with a more phasic character (extensor digitorum longus), whereas the opposite is true of denervation. In the intact animals, starvation greatly increased the amount of atrophy following denervation. In the adrenalectomized animals, starvation had no effect on the amounts of atrophy following denervation. Furthermore, adrenalectomy virtually eliminated the fiber-type differences in the amount of atrophy following denervation. In addition, a comparison between denervated muscles from intact animals and adrenalectomized animals subjected to starvation demonstrates that all denervated muscles from the adrenalectomized animals atrophy less. Finally, it was observed that although an adrenalectomized animal can tolerate 6 days of starvation, an adrenalectomized-castrated animal cannot tolerate even short periods of starvation. The difference appears to be due to low amounts of corticosterone of testicular origin.

Human growth hormone treatment of hypophysectomized rats increases the proportion of type-1 fibres in skeletal muscle

1989 ◽  
Vol 123 (3) ◽  
pp. 429-NP ◽  
Author(s):  
C. M. Ayling ◽  
B. H. Moreland ◽  
J. M. Zanelli ◽  
D. Schulster
Keyword(s):  
Skeletal Muscle ◽  
Fibre Type ◽  
Extensor Digitorum Longus ◽  
Human Growth ◽  
Hormone Treatment ◽  
Pituitary Hormones ◽  
Extensor Digitorum ◽  
Replacement Treatment ◽  
Hypophysectomized Rats

ABSTRACT The studies describe alterations after hypophysectomy in the proportion of the type-1 and type-2 fibres in rat skeletal muscles, and the effects of replacement treatment with pituitary human (h) GH. Cytochemical analysis of myosin ATPase, succinate dehydrogenase and lactate dehydrogenase activities in sections of rat hind limb muscles were used as markers of fibre type and revealed that hypophysectomy reduced the proportion of type-1 fibres by 50% in soleus and in extensor digitorum longus muscles. This reduction in the proportion of type-1 fibres was accompanied by the appearance of transitional fibres (type 2C/1B). Following seven daily injections of hGH (60 mIU/day) to hypophysectomized rats, the proportion of type-1 fibres in both soleus and in extensor digitorum longus was increased with a concomitant reduction in the number of transitional fibres. After 11 days of treatment, all these transitional fibres had reverted back to type-1 fibres. Only hGH was observed to elicit this effect; injections of other pituitary hormones had no effect on the proportions of these transitional fibres. These alterations in fibre type occurred more rapidly than the changes reported after prolonged electrical stimulation of muscle or following extended exercise. These findings suggest that hypophysectomy and GH injection can result in a rapid alteration in the fibre composition of skeletal muscle, which may have important implications in terms of the resistance to fatigue and speed of contraction of the muscle. Journal of Endocrinology (1989) 123, 429–435

scholarly journals Identification in skeletal muscle of a distinct extracellular pool of amino acids, and its role in protein synthesis

1971 ◽  
Vol 121 (5) ◽  
pp. 817-827 ◽  
Author(s):  
R. C. Hider ◽  
E. B. Fern ◽  
D. R. London
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Incubation Medium ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Longus Muscle ◽  
Kinetics Of

1. The kinetics of radioactive labelling of extra- and intra-cellular amino acid pools and protein of the extensor digitorum longus muscle were studied after incubations with radioactive amino acids in vitro. 2. The results indicated that an extracellular pool could be defined, the contents of which were different from those of the incubation medium. 3. It was concluded that amino acids from the extracellular pool, as defined in this study, were incorporated directly into protein.

Changes in [Ca2+]i induced by several glucose transport-enhancing stimuli in rat epitrochlearis muscle

2003 ◽  
Vol 94 (5) ◽  
pp. 1813-1820 ◽  
Author(s):  
Shin Terada ◽  
Isao Muraoka ◽  
Izumi Tabata
Keyword(s):  
Glucose Transport ◽  
Quantitative Information ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Concentration Dependent Manner ◽  
Fura 2 ◽  
Sprague Dawley Rats ◽  
Intracellular Ca ◽  
Resting Muscle ◽  
Krebs Henseleit Buffer

The purpose of the present investigation was to establish a method for estimating intracellular Ca2+ concentrations ([Ca2+]i) in isolated rat epitrochlearis muscles. Epitrochlearis muscles excised from 4-wk-old male Sprague-Dawley rats were loaded with a fluorescent Ca2+indicator, fura 2-AM, for 60–90 min at 35°C in oxygenated Krebs-Henseleit buffer. After fura 2 loading and subsequent 20-min incubation, the intensities of 500-nm fluorescence, induced by 340- and 380-nm excitation lights (Ftotal340 and Ftotal380), were measured. The fluorescences specific to fura-2 (Ffura 2340 and Ffura 2380) were calculated by subtracting the non-fura 2-specific component from Ftotal340 and Ftotal380, respectively. The ratio of Ffura 2340 to Ffura 2380 was calculated as R, and the change in the ratio from the baseline value (ΔR) was used as an index of the change in [Ca2+]i. In resting muscle, ΔR was stable for 60 min. Incubation for 20 min with caffeine (3–10 mM) significantly increased ΔR in a concentration-dependent manner. Incubation with hypoxic Krebs-Henseleit buffer for 10–60 min significantly elevated ΔR, depending on the duration of the incubation. Incubation with 50 μM N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide for 20 min significantly elevated ΔR ( P < 0.05). No significant increases in ΔR were observed during incubation for 20 min with 2 mM 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside or with 2 mU/ml insulin. These results demonstrated that, by using the fura 2-AM fluorescence method, the changes in [Ca2+]i can be monitored in the rat epitrochlearis muscle and suggest that the method can be utilized to observe quantitative information regarding [Ca2+]i that may be involved in contraction- and hypoxia-stimulated glucose transport activity in skeletal muscle.

Recombinant human regenerating gene 4 attenuates the severity of osteoarthritis by promoting the proliferation of articular chondrocyte in an animal model

2021 ◽  
Vol 14 ◽  
Author(s):  
Xue-jia Li ◽  
Fei Zhu ◽  
Bo Li ◽  
Dong Zhang ◽  
Cheng-Wei Liang
Keyword(s):  
Risk Factors ◽  
Animal Model ◽  
Sprague Dawley ◽  
Articular Chondrocyte ◽  
Chondrocyte Proliferation ◽  
Histological Changes ◽  
Proper Role ◽  
Sprague Dawley Rats ◽  
Gene 4

Introduction: Osteoarthritis (OA) is a dominant cause of morbidity and disability. As a chronic disease, its etiological risk factors and most therapies at present, are empirical and symptomatic. Regenerating gene 4 (Reg4) is involved in cell growth, survival, regeneration, adhesion, and resistance to apoptosis, which are partially thought to be the pathogenic mechanisms of OA. However, the proper role of Reg4 in OA is still unknown. Methods: In this study, a consecutive administration of rhReg4 was applied to normal Sprague-Dawley rats or rats after OA induction. Histological changes and chondrocyte proliferation in the articular cartilage were measured. Results: We found that RhReg4 promotes chondrocyte proliferation in normal rats, and RhReg4 attenuated the severity of OA in rats by promoting chondrocytes’ proliferation in OA rats. Conclusion: In conclusion, recombinant human regenerating gene 4 (rhReg4) attenuates the severity of osteoarthritis in OA animal models and may be used as a new method for the treatment of osteoarthritis.

Effect of low-potassium diet on rat exercise hyperthermia and heatstroke mortality

1981 ◽  
Vol 51 (1) ◽  
pp. 8-13 ◽  
Author(s):  
R. W. Hubbard ◽  
M. Mager ◽  
W. D. Bowers ◽  
I. Leav ◽  
G. Angoff ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Plasma Potassium ◽  
Heat Illness ◽  
Sprague Dawley ◽  
Heat Gain ◽  
Sprague Dawley Rats ◽  
Low Potassium ◽  
Work Done ◽  
Low K

A total of 182 male Sprague-Dawley rats weighing 250–300 g were fed either a control (n = 122) diet for 32 days. The diets contained either 125 or 8 meq potassium/kg, respectively. Rats fed the low-K diet gained weight at only one-third the rate of controls (1.7 vs. 5.2 g/day), and their skeletal muscle and plasma potassium levels were reduced by 28 and 47%, respectively. When run to exhaustion at either 15 or 20 degrees C, low K+-fed rats accomplished less than one-half of the work done by the controls (26 vs. 53 kg. m) but exhibited a markedly greater rate of heat gain per kilogram-meter of work than controls (0.12 vs. 0.05 degrees C)ambient temperature of 20 degrees C, the rats of the low-K+ group despite large differences in body weight (-25%), run time temperature and twice (33 vs 17%) the mortality rate of the controls. Postexercise increases in circulating potassium (less than 90%) of heat-injured rats raised the plasma levels of low K+-fed rats to normal (5.9 +/- 2.2 meq/l). These results appear to characterize the existence of an insidious and, therefore, undocumented form of fatal exertion-induced heat illness.

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