Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The muscle fiber types and sizes in the M. stapedius (middle ear muscle) of the domestic chicken, Gallus gallus were determined histochemically on the basis of their reactions to myofibrillar adenosine triphosphatase (mATPase), succinic dehydrogenase and NADH diaphorase. Only type II fibers were identified at pH 9.4 and 4.2. At pH 4.6 three levels of activity were seen: high, intermediate and low. With the staining techniques three subtypes of fibers for oxidative enzymes, Types II1 (highly glycolytic), II12 (intermediately glycolytic and lipolytic) and II123 (highly lipolytic) were identified. Fiber diameter was also measured for the different fiber types. The average fiber diameter was around 20 micron for each fiber type. Although similar in size, the fiber types were markedly different in their histochemical properties. These findings plus those of earlier physiological studies suggest that the M. stapedius of G. gallus is a fast twitch, muscle with fibers of similar diameter showing mainly fatigue resistance characteristics.
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PMID:A histochemical characterization of muscle fiber types in the avian M. stapedius. 288 51

Myofibrillar proteins in muscles of the claws and abdomen of lobster, Homarus americanus, and the claws of fiddler crab, Uca pugnax, and land crab, Gecarcinus lateralis, have been analyzed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Fibers contained numerous isoforms of structural and regulatory proteins in assemblages correlated with fiber type. One fast (F) and two slow (S1 and S2) fibers were identified. All F fibers possessed two isoforms of paramyosin (P1 and P2), while all slow fibers, with the exception of Uca major claw, contained only the P2 variant. S1 and S2 fibers were distinguished by the distribution of a large isoform of troponin-T (T1; Mr = 55,000); S2 fibers in all three species contained T1 in addition to one or two smaller-molecular-weight variants usually associated with S1 fibers. In order to determine whether the slow fibers differed in histochemical properties, land crab claw closer muscle was cryosectioned and stained for myofibrillar ATPase and NADH diaphorase activities. Most S2 fibers had lower ATPase and higher NADH diaphorase activities than S1 fibers, which indicated that S2 fibers had a lower rate of contraction and were more fatigue-resistant than S1 fibers. It is proposed that the S1 and S2 fibers defined by biochemical and histochemical criteria are identical to the slow-twitch and tonic fibers, respectively characterized physiologically.
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PMID:Histochemical and biochemical characterization of two slow fiber types in decapod crustacean muscles. 296 38

A comparison of the anatomy, fiber type profiles, and contractile properties of the wrist flexor muscles was undertaken in the cat. Isometric contractile characteristics were measured for each muscle. Three muscle fiber types, FG, FOG, and SO, were differentiated by staining cross sections of each muscle for ATPase, NADH diaphorase, SDH, and alpha-GPD activities. The wrist flexor muscles ranged from less than 1% to 49% SO fiber content; with two of the five heads of the flexor digitorium profundus (FDP) having 1% or less SO fibers (FDP1-1.07%, FDP5-0.81%) and the humeral head of the flexor carpi ulnaris muscle (FCUh) having the greatest content of SO fibers. The mean contraction time (CT) plus one-half relaxation time for an isometric twitch was correlated with the percentage of SO fibers and ranged from 40.5 to 111.8 ms. Except for the FCU (37ms), the CT was less than 25 ms for the wrist flexor muscles. The uniarticular wrist flexor muscles, the flexor carpi radialis (FCR), and the FCU had the highest percentage of SO fibers and were more fatigue-resistant that the multiarticular muscles. Considerable differences exist in muscle structure, fiber type proportions, and contractile properties between the FCR and FCU, which may be related to functional differences between the two sides of the wrist that may exist during the placement of the foot during locomotion.
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PMID:Morphological organization and contractile properties of the wrist flexor muscles in the cat. 725 81