Collagen of slow twitch and fast twitch muscle fibres in different types of rat skeletal muscle

1984 ◽  
Vol 52 (2) ◽  
pp. 235-242 ◽  
Author(s):  
V. Kovanen ◽  
H. Suominen ◽  
E. Heikkinen
1987 ◽  
Vol 65 (2) ◽  
pp. 272-273 ◽  
Author(s):  
Michael Chua ◽  
Angela F. Dulhunty

The action of the tranquilizer diazepam on rat skeletal muscle showed that relaxation of isometric twitches is controlled by different processes in extensor digitorum longus (fast-twitch) and soleus (slow-twitch) muscles. Diazepam caused an increase in the amplitude of twitches in fibres from both muscles but increased the twitch duration only in soleus. The amplitude of fused tetani were reduced in both muscles and the rate of relaxation after the tetanus slowed by as much as 34% when the amplitude of the tetanus was reduced by only 11%. The slower tetanic relaxation indicated that calcium uptake by the sarcoplasmic reticulum was slower than normal in slow- and fast-twitch fibres. We conclude therefore that calcium uptake by the sarcoplasmic reticulum is rate limiting for twitch relaxation in slow-twitch but not fast-twitch fibres and suggest that calcium binding to parvalbumin controls relaxation in the fast fibres.


1996 ◽  
Vol 271 (4) ◽  
pp. C1250-C1255 ◽  
Author(s):  
M. Wada ◽  
T. Okumoto ◽  
K. Toro ◽  
K. Masuda ◽  
T. Fukubayashi ◽  
...  

Myosin of human skeletal muscles was analyzed by means of several electrophoretic techniques. Myosin heavy chain (HC)-IIa-and HC-IIb-based isomyosins were identified by pyrophosphate-polyacrylamide gel electrophoresis (PP-PAGE). The electrophoretic mobilities of these fast-twitch muscle isomyosins differed in the order HC-IIa triplets < HC-IIb triplets. To determine the subunit composition of myosin molecules that function in intact muscle, two-dimensional electrophoresis in which the first and second dimensions were PP-PAGE and sodium dodecyl sulfate-PAGE, respectively, was also performed. Slow-twitch muscle isomyosin contained, in addition to slow-twitch light chain (LC) and HC-I isoforms, appreciable amounts of LC-2f, HC-IIa, and HC-IIb isoforms, and fast-twitch muscle isomyosin consisted of LC-2s and HC-I isoforms as well as fast-twitch LC and HC isoforms. Without consideration of HC- and slow-twitch alkali LC heterodimers, at least 31 possible isomyosins are derived from these findings on the subunit composition of isomyosins in human skeletal muscle.


1984 ◽  
Vol 222 (1228) ◽  
pp. 401-408 ◽  

An analysis has been performed of the native myosin isoenzyme com position of isolated skeletal muscle fibres from Xenopus laevis with welldefined isotonic contraction properties. Fast twitch ‘ white ’ (type 1) fibres contained three isomyosins; fast twitch ‘red ’ (type 2) fibres showed two major myosin bands with migration velocities very similar to those of the two slower bands in type 1. Slow twitch (type 3) fibres yielded a single, slowly migrating band as did slow tonic (type 5) fibres, whereas the myosin from type 4 (very slow twitch, ‘intermediate’) fibres migrated with a somewhat higher mobility. The results suggest that amphibian skeletal muscle may possess the principal fibre types found in mammals and birds.


1979 ◽  
Vol 80 (2) ◽  
pp. 372-384 ◽  
Author(s):  
A O Jorgensen ◽  
V Kalnins ◽  
D H MacLennan

Ca++-Mg++-dependent ATPase and calsequestrin, the major intrinsic and extrinsic proteins, respectively, of the sarcoplasmic reticulum, were localized in cryostat sections of adult rat skeletal muscle by immunofluorescent staining and phase-contrast microscopy. Relatively high concentrations of both the ATPase and calsequestrin were found in fast-twitch myofibers while a very low concentration of the ATPase and a moderate concentration of calsequestrin were found in slow-twitch myofibers. These findings are consistent with previous biochemical studies of the isolated sarcoplasmic reticulum of slow-twitch and fast-twitch mammalian muscles. The distribution of the ATPase in muscle fibers is distinctly different from that of calsequestrin. While calsequestrin is present only near the interface between the I- and A-band regions of the sarcomere, the ATPase is found throughout the I-band region as well as in the center of the A-band region. In comparing these results with in situ ultrastructural studies of the distribution of sarcoplasmic reticulum in fast-twitch muscle, it appears that the ATPase is rather uniformly distributed throughout the sarcoplasmic reticulum while calsequestrin is almost exclusively confined to those regions of the membrane system which correspond to terminal cisternae. Fluorescent staining with these antisera was not observed in vascular smooth muscle cells present in the cryostat sections of the mammalian skeletal muscle used in this study.


2006 ◽  
Vol 290 (1) ◽  
pp. R233-R240 ◽  
Author(s):  
Bankim A. Bhatt ◽  
John J. Dube ◽  
Nikolas Dedousis ◽  
Jodie A. Reider ◽  
Robert M. O’Doherty

Increased activity of proinflammatory/stress pathways has been implicated in the pathogenesis of insulin resistance in obesity. However, the effects of obesity on the activity of these pathways in skeletal muscle, the major insulin-sensitive tissue by mass, are poorly understood. Furthermore, the mechanisms that activate proinflammatory/stress pathways in obesity are unknown. The present study addressed the effects of diet-induced obesity (DIO; 6 wk of high-fat feeding) and acute (6-h) hyperlipidemia (HL) in rats on activity of IKK/IκB/NF-κB c-Jun NH2-terminal kinase, and p38 MAPK in three skeletal muscles differing in fiber type [superficial vastus (Vas; fast twitch-glycolytic), soleus (Sol; slow twitch-oxidative), and gastrocnemius (Gas; mixed)]. DIO decreased the levels of the IκBα in Vas (24 ± 3%, P = 0.001, n = 8) but not in Sol or Gas compared with standard chow-fed controls. Similar to DIO, HL decreased IκBα levels in Vas (26 ± 5%, P = 0.006, n = 6) and in Gas (15 ± 4%, P = 0.01, n = 7) but not in Sol compared with saline-infused controls. Importantly, the fiber-type-dependent effects on IκBα levels could not be explained by differential accumulation of triglyceride in Sol and Vas. HL, but not DIO, decreased phospho-p38 MAPK levels in Vas (41 ± 7% P = 0.004, n = 6) but not in Sol or Gas. Finally, skeletal muscle c-Jun NH2-terminal kinase activity was unchanged by DIO or HL. We conclude that diet-induced obesity and acute HL reduce IκBα levels in rat skeletal muscle in a fiber-type-dependent manner.


Author(s):  
R. Wróblewski ◽  
W. Gremski ◽  
G. M. Roomans ◽  
R. Nordemar ◽  
L. Edström

Many diseases of the human skeletal muscle involve an atrophy of the muscle fibres. In some cases mainly one of the fibre types is affected. The fibre typing system used in this study is that of Padykula and Herman, 1955 and distinguishes between type I fibres which presumably correspond to the slow-twitch fibres and type II fibres which are the fast-twitch fibres. The type II fibres can be divided into type II A, II B and II C fibres. Recent advances in instrumentation and tissue preparation have permitted an investigation of the elemental composition of individual muscle fibres of known fibre type with the aim of comparing healthy and atrophied muscle fibres.In this study we have examined ten patients suffering from rheumatoid arthritis, two patients suffering from Parkinson's disease and two patients with upper motor lesions. As a control group we have examined muscles from eight healthy controls of the same age.


1988 ◽  
Vol 66 (12) ◽  
pp. 1555-1559 ◽  
Author(s):  
J. Gorski ◽  
W. C. Miller ◽  
W. K. Palmer ◽  
L. B. Oscai

One purpose of this study was to determine if colchicine increased intracellular alkaline triglyceride (TG) lipase activity above control levels in rat skeletal muscle. The second aim was to determine the effects of colchicine treatment on the concentration of TG in skeletal muscle. The results show that colchicine was a potent inducer of alkaline TG lipase activity, increasing enzyme activity approximately twofold in slow-twitch red, fast-twitch red, and fast-twitch white muscle types. It was found that in slow-twitch red soleus and fast-twitch red vastus, the two muscle groups with the highest levels of enzyme activity, 76% or more of enzyme activity resides in the intracellular compartment. These results provide evidence that colchicine blocks the export of alkaline TG lipase from skeletal muscle cells similar to that seen in the heart. The finding that TG were reduced at a time when enzyme activity was elevated suggests that intracellular alkaline TG lipase may be playing a role in the hydrolysis of the intramuscular TG droplet.


1992 ◽  
Vol 73 (6) ◽  
pp. 2713-2716 ◽  
Author(s):  
J. M. Ren ◽  
J. O. Holloszy

AMP deaminase catalyzes deamination of the AMP formed in contracting muscles to inosine 5′-monophosphate (IMP). Slow-twitch muscle has only approximately 30% as high a level of AMP deaminase activity as fast-twitch muscle in the rat, and rates of IMP formation during intense contractile activity are much lower in slow-twitch muscle. We found that feeding the creatine analogue beta-guanidinopropionic acid (beta-GPA) to rats, which results in creatine depletion, causes a large decrease in muscle AMP deaminase. This adaptation was used to evaluate the role of AMP deaminase activity level in accounting for differences in IMP production in slow-twitch and fast-twitch muscles. beta-GPA feeding for 3 wk lowered AMP deaminase activity in fast-twitch epitrochlearis muscle to a level similar to that found in the normal slow-twitch soleus muscle but had no effect on the magnitude of the increase in IMP in response to intense contractile activity. Despite a similar decrease in ATP in the normal soleus and the epitrochlearis from beta-GPA-fed rats, the increase in IMP was only approximately 30% as great in the soleus in response to intense contractile activity. These results demonstrate that the accumulation of less IMP in slow- compared with fast-twitch skeletal muscle during contractile activity is not due to the lower level of AMP deaminase in slow-twitch muscle.


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