scholarly journals Myosin Heavy Chain Expression Can Vary over the Length of Jaw and Leg Muscles

2016 ◽  
Vol 201 (2) ◽  
pp. 130-137 ◽  
Author(s):  
J.A.M. Korfage ◽  
K.E. Kwee ◽  
V. Everts ◽  
G.E.J. Langenbach
Keyword(s):  
Myosin Heavy Chain ◽  
Muscle Fiber ◽  
Heavy Chain ◽  
Fiber Type ◽  
Staining Intensity ◽  
Medial Gastrocnemius ◽  
Hybrid Fibers ◽  
Leg Muscles ◽  
Myhc Isoforms ◽  
Myhc Expression

Muscle fiber type classification can be determined by its myosin heavy chain (MyHC) composition based on a few consecutive sections. It is generally assumed that the MyHC expression of a muscle fiber is the same over its length since neural stimulation and systemic influences are supposed to be the same over its length. We analyzed this in detail in three muscle types: the temporalis (closer) and digastricus (opener; both first brachial arch), and the medial gastrocnemius (somite). Sections of the muscles were incubated with monoclonal antibodies against various MyHC isoforms, and the distribution of these isoforms within individual fibers was followed over a distance of approximately 1 mm. The staining intensity of a fiber was measured and compared with the other fibers in the section. In the temporalis, digastricus, and gastrocnemius, 46, 11, and 15%, respectively, of their MyHC-I fibers showed a variation in the staining intensity over the length of their fibers, as well as 47, 87, and 22%, respectively, of their MyHC-IIA fibers. Most variable fibers were found amongst those with an overall relative intermediate staining intensity, which are presumably hybrid fibers. We conclude that different parts of a muscle fiber can have different fiber type compositions and, thus, contractile properties. Some muscle parts might reach their maximum contraction peak sooner or later than a muscle part a few microns further away. Next to stimulation by the nerve and systemic influences, local influences might also have an impact on the MyHC expression of the fiber.

scholarly journals Immunohistochemical Analysis of Myosin Heavy Chain Expression in Laryngeal Muscles of the Rabbit, Cat, and Baboon

2008 ◽  
Vol 56 (10) ◽  
pp. 929-950 ◽  
Author(s):  
Hannah S. Rhee ◽  
Joseph F.Y. Hoh
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Fiber Type ◽  
Immunohistochemical Analysis ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Laryngeal Muscles ◽  
Myhc Isoforms ◽  
Posterior Cricoarytenoid ◽  
Myhc Expression

We studied myosin heavy chain (MyHC) expression and fiber type distribution in laryngeal muscles in the rabbit, cat, and baboon using immunohistochemistry with highly MyHC-specific antibodies. Two types of variation in MyHC expression were found: between muscles of different function within species and within specific muscles between species. Within species, thyroarytenoid (Ta), an adductor, had faster MyHCs and fiber type profiles than the abductor, posterior cricoarytenoid (PCA), which expressed faster MyHCs than the vocal fold tensor, cricothyroid (CT). Between species, laryngeal muscles generally expressed faster MyHCs in small animals than in larger ones: extraocular (EO) MyHC was expressed in the Ta and PCA of the rabbit but not in the cat and baboon, whereas 2B MyHC was expressed in these muscles of the cat but not of the baboon. The CT expressed only MyHC isoforms and fiber types found in the limb muscles of the same species. These results are discussed in light of the hypothesis that the between-species variations in laryngeal muscle fiber types are evolutionary adaptations in response to changes in body mass and respiratory frequency. Within-species variations in fiber types ensure that protective closure of the glottis is always faster than movements regulating airflow during respiration.

Heterogeneity of myosin heavy-chain expression in fast-twitch fiber types of mature avian pectoralis muscle

1996 ◽  
Vol 74 (5) ◽  
pp. 715-728 ◽  
Author(s):  
B. W. C. Rosser ◽  
D. M. Waldbillig ◽  
M. Wick ◽  
E. Bandman
Keyword(s):  
Monoclonal Antibodies ◽  
Myosin Heavy Chain ◽  
Muscle Fiber ◽  
Heavy Chain ◽  
Fiber Types ◽  
Pectoralis Muscle ◽  
Western Blots ◽  
Myhc Isoforms ◽  
Fast Twitch ◽  
Myhc Expression

The aims of this study are to investigate the diversity of myosin heavy-chain (MyHC) expression among avian fast-twitch fibers, and to test the hypothesis that dissimilar MyHC isoforms are found in each of the principal avian fast-twitch fiber types. MyHCs within the muscle fibers of the pectoralis of 31 species of bird are characterized using immunocytochemical methods. A library of 11 monoclonal antibodies previously produced against chicken MyHCs is used. The specificity of these antibodies for MyHCs in each of the muscles studied is confirmed by Western blots. The results show that avian fast-twitch glycolytic fibers and fast-twitch oxidative-gylcolytic fibers can contain different MyHCs. Among the species studied, there is also a conspicuous variety of MyHC isoforms expressed. In addition, the results suggest that two epitopes are restricted to chickens and closely allied gallinaceous birds. There are no apparent correlations between MyHC epitope and presupposed contractile properties. However, the presence of different isoforms in different fast-twitch fiber types suggests a correlation between isoform and contractile function.Key words: muscle, fiber, myosin, avian.

Enzymatic plasticity of medial gastrocnemius fibers in the adult chronic spinal cat

1990 ◽  
Vol 259 (3) ◽  
pp. C507-C514 ◽  
Author(s):  
B. Jiang ◽  
R. R. Roy ◽  
V. R. Edgerton
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Fiber Type ◽  
Motor Units ◽  
Glycolytic Enzyme ◽  
Medial Gastrocnemius ◽  
Fiber Types ◽  
Cross Sectional ◽  
Fast Myosin ◽  
Weight Support

The metabolic plasticity of single fibers in adult cat medial gastrocnemius (MG) 6 mo after complete spinal cord transection (Sp) at T12-T13 was studied. Some Sp cats were trained to weight support (Sp-WS) 30 min/day beginning 1 mo posttransection. Cross-sectional area, succinate dehydrogenase (SDH), alpha-glycerophosphate dehydrogenase (GPD), and myofibrillar adenosinetriphosphatase (ATPase) activities were determined in fibers identified in frozen serial sections. Fibers were categorized as light or dark based on myosin ATPase staining, alkaline preincubation. The percentage of dark ATPase fibers was higher in Sp and Sp-WS (approximately 85%) than in control (approximately 60%). All dark ATPase fibers reacted positively to a fast myosin heavy chain monoclonal antibody. In both spinal groups, a higher percentage of dark ATPase fibers reacted to both fast and slow myosin heavy chain antibodies than in controls. Neither Sp nor Sp-WS cats showed fiber atrophy. Compared with control, SDH activity was decreased in both fiber types of Sp cats. Daily weight-support training ameliorated this adaptation. There were no differences among the three groups in mean GPD and ATPase activities for either fiber type. There was a slight tendency, however, for spinal cats to have higher GPD and ATPase activities (independent of type) than control, probably reflecting the larger proportion of dark ATPase fibers in these cats. These observations indicate that 6 mo after spinalization in adult cats, some of the fibers of a fast muscle became "faster" and developed oxidative and glycolytic enzyme profiles that normally are exhibited in fast fatigable motor units.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Muscle fiber type characterization and myosin heavy chain (MyHC) isoform expression in Mediterranean buffaloes

Meat Science ◽  
2011 ◽  
Vol 88 (3) ◽  
pp. 535-541 ◽  
Author(s):  
C.L. Francisco ◽  
A.M. Jorge ◽  
M. Dal-Pai-Silva ◽  
F.R. Carani ◽  
L.C. Cabeço ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Muscle Fiber ◽  
Heavy Chain ◽  
Fiber Type ◽  
Muscle Fiber Type ◽  
Isoform Expression

Age-Related Alterations in Myosin Heavy Chain Isoforms in Rat Intrinsic Laryngeal Muscles

2002 ◽  
Vol 111 (11) ◽  
pp. 962-967 ◽  
Author(s):  
Tatsutoshi Suzuki ◽  
Diane M. Bless ◽  
Nadine P. Connor ◽  
Charles N. Ford ◽  
Kyungah Lee ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Muscle Fiber ◽  
Heavy Chain ◽  
Fiber Type ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Myosin Heavy Chain Isoforms ◽  
Laryngeal Muscles ◽  
Age Related ◽  
Posterior Cricoarytenoid

Deficits in voice and swallowing are found in the elderly, but the underlying neuromuscular mechanisms are unclear. A potential mechanism may be denervation-induced muscle fiber transformation to a slower-contracting type of muscle fiber. This study examined young, old, and denervated rat laryngeal muscles (lateral thyroarytenoid, lateral cricoarytenoid, and posterior cricoarytenoid) to examine differences in myosin heavy chain (MHC) composition. Results of sodium dodecyl sulfate–polyacrylamide gel electrophoresis analyses indicated that all muscles were composed predominately of type IIB MHC. With aging and denervation, type IIB was reduced and type IIX, a slower-contracting isoform, was increased in the lateral thyroarytenoid and lateral cricoarytenoid muscles. In the posterior cricoarytenoid muscle, the MHC composition was relatively unchanged. These findings suggest that aging may affect laryngeal adductory function by altering muscle fiber type composition to a slower-contracting isoform, in a manner similar to that observed with denervation.

scholarly journals Divergent effects of cold water immersion versus active recovery on skeletal muscle fiber type and angiogenesis in young men

2018 ◽  
Vol 314 (6) ◽  
pp. R824-R833 ◽  
Author(s):  
Randall F. D’Souza ◽  
Nina Zeng ◽  
James F. Markworth ◽  
Vandre C. Figueiredo ◽  
Llion A. Roberts ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Muscle Fiber ◽  
Heavy Chain ◽  
Cold Water ◽  
Fiber Type ◽  
Water Immersion ◽  
Group Versus ◽  
Cold Water Immersion ◽  
Muscle Fiber Type ◽  
Active Recovery

Resistance training (RT) increases muscle fiber size and induces angiogenesis to maintain capillary density. Cold water immersion (CWI), a common postexercise recovery modality, may improve acute recovery, but it attenuates muscle hypertrophy compared with active recovery (ACT). It is unknown if CWI following RT alters muscle fiber type expression or angiogenesis. Twenty-one men strength trained for 12 wk, with either 10 min of CWI ( n = 11) or ACT ( n = 10) performed following each session. Vastus lateralis biopsies were collected at rest before and after training. Type IIx myofiber percent decreased ( P = 0.013) and type IIa myofiber percent increased with training ( P = 0.012), with no difference between groups. The number of capillaries per fiber increased from pretraining in the CWI group ( P = 0.004) but not the ACT group ( P = 0.955). Expression of myosin heavy chain genes ( MYH1 and MYH2), encoding type IIx and IIa fibers, respectively, decreased in the ACT group, whereas MYH7 (encoding type I fibers) increased in the ACT group versus CWI ( P = 0.004). Myosin heavy chain IIa protein increased with training ( P = 0.012) with no difference between groups. The proangiogenic vascular endothelial growth factor protein decreased posttraining in the ACT group versus CWI ( P < 0.001), whereas antiangiogenic Sprouty-related, EVH1 domain-containing protein 1 protein increased with training in both groups ( P = 0.015). Expression of microRNAs that regulate muscle fiber type (miR-208b and -499a) and angiogenesis (miR-15a, -16, and -126) increased only in the ACT group ( P < 0.05). CWI recovery after each training session altered the angiogenic and fiber type-specific response to RT through regulation at the levels of microRNA, gene, and protein expression.

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