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.

Atypical Myosin Heavy Chain in Rat Laryngeal Muscle

1995 ◽  
Vol 104 (3) ◽  
pp. 237-245 ◽  
Author(s):  
John M. DelGaudio ◽  
William R. Carroll ◽  
James J. Sciote ◽  
Ramon M. Esclamado
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Fiber Type ◽  
Sodium Dodecyl ◽  
Laryngeal Muscles ◽  
Laryngeal Muscle ◽  
Posterior Cricoarytenoid Muscle ◽  
Limb Muscles ◽  
Electrophoretic Techniques ◽  
Posterior Cricoarytenoid

The myosin content of rat posterior cricoarytenoid and thyroarytenoid muscles was described by means of histochemical, immunohistochemical, and electrophoretic techniques. Laryngeal muscles were dissected and frozen, together with other muscles (extraocular, diaphragm, extensor digitorum longus, and soleus) for comparative purposes, then sectioned serially and stained: 1) histochemically for myofibrillar adenosine triphosphatase reactivity and 2) immunohistochemically for myosin heavy chain (MHC) content with six different antibodies. Other portions of the muscle samples were electrophoresed by a glycerol sodium dodecyl sulfatepolyacrylamide gel electrophoresis technique that separates the MHC protein into its specific isoforms. In electrophoretic comparison it limb muscles, the laryngeal muscles contained an additional MHC band we designated as type IIL (type II laryngeal) MHC. On histochemical and immunohistochemical staining, no fibers from the thyroarytenoid muscle and few fibers from the posterior cricoarytenoid muscle could be classified according to the standard fiber type categories established for limb muscles (types I, IIA, IIB, and IIX). These laryngeal muscle fibers appear to represent an atypical fiber type.

Myosin Heavy Chain Expression in Human Laryngeal Muscle Fibers

2000 ◽  
Vol 109 (2) ◽  
pp. 216-220 ◽  
Author(s):  
Sophie Périé ◽  
Onnik Agbulut ◽  
Jean Lacau St Guily ◽  
Gillian Sandra Butler-Browne
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Biochemical Analysis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Laryngeal Muscles ◽  
Immature Development ◽  
Posterior Cricoarytenoid ◽  
Human Limb ◽  
Intrinsic Laryngeal Muscles

Since the intrinsic laryngeal muscles in humans are involved in specialized functions, one may suppose that this would be associated with the expression of specific myosin heavy chain (MHC) isoforms, as has been reported for the rat, dog, and rabbit. In order to determine which MHCs are expressed in the human laryngeal muscles, biochemical analysis using sodium dodecyl sulfate—polyacrylamide gel electrophoresis was performed. Thyroarytenoid and posterior cricoarytenoid muscles were obtained from a 7-month-old infant and 4 adults. In the adult human laryngeal muscles, 3 bands were resolved identical to those previously described in the human limb muscles (I, IIA, and IIB MHCs). In contrast, muscles from the infant also expressed fetal MHC and a novel MHC not observed in other human skeletal muscles. This novel band migrated at the same level as the laryngeal MHC previously described in the rat. Since these 2 isoforms disappear in the adult, the persistence in the infant could be correlated with the immature development of laryngeal functions and, in particular, phonation.

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.

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