Abstract
In the present study we aimed to determine the functional properties and the myosin heavy chain (MHC) isoform composition of single chemically skinned fibres from the vocal muscle of four adult men (age: 55-67 years). Single fibres, dissected from the bioptic samples, were chemically skinned and isometric tension (P0) and maximal shortening velocity (V0) were measured at pCa 4.6. MHC and myosin light chain (MLC) composition of fibre segments and MHC distribution of the biopsy samples were analysed by SDS-poly-acrylamide gel electrophoresis (SDS - PAGE) and densitometry. Four MHC isoforms (1,2A, 2X and a fourth isoform, provisionally called L) and five MLC isoforms (MLC1s, MLC1f, MLC3f, MLC2f, MLC2s) were identified. The major findings of this study were: (1) fast MHC isoforms (in particular MHC-2A) and fast fibres were predominant, (2) one-third of the fibres were mixed or hybrid, i.e. expressed more than one MHC isoform, (3) V0 and P0 values were determined by the MHC isoform composition and mixed fibres showed functional properties which were intermediate between pure fibres; MHC-L was associated with V0 values similar to those of MHC-2A, (4) compared with limb muscles, V0 values of laryngeal fibres were similar to those of limb muscle fibres containing the same MHC isoform whereas P0 values were lower for slow and fast 2X fibres and similar for fibres expressing MHC-2A.
| Original language | English |
|---|---|
| Pages (from-to) | 187-195 |
| Number of pages | 9 |
| Journal | Journal of Muscle Research and Cell Motility |
| Volume | 23 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2002 |
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ASJC Scopus subject areas
- Physiology
- Clinical Biochemistry
- Endocrinology
- Cell Biology
Cite this
Contractile properties and myosin heavy chain isoform composition in single fibre of human laryngeal muscles. / D'Antona, Giuseppe; Megighian, Aram; Bortolotto, Susan; Pellegrino, Maria Antonietta; Marchese-Ragona, Rosario; Staffieri, Alberto; Bottinelli, Roberto; Reggiani, Carlo.
In: Journal of Muscle Research and Cell Motility, Vol. 23, No. 3, 2002, p. 187-195.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Contractile properties and myosin heavy chain isoform composition in single fibre of human laryngeal muscles
AU - D'Antona, Giuseppe
AU - Megighian, Aram
AU - Bortolotto, Susan
AU - Pellegrino, Maria Antonietta
AU - Marchese-Ragona, Rosario
AU - Staffieri, Alberto
AU - Bottinelli, Roberto
AU - Reggiani, Carlo
PY - 2002
Y1 - 2002
N2 - In the present study we aimed to determine the functional properties and the myosin heavy chain (MHC) isoform composition of single chemically skinned fibres from the vocal muscle of four adult men (age: 55-67 years). Single fibres, dissected from the bioptic samples, were chemically skinned and isometric tension (P0) and maximal shortening velocity (V0) were measured at pCa 4.6. MHC and myosin light chain (MLC) composition of fibre segments and MHC distribution of the biopsy samples were analysed by SDS-poly-acrylamide gel electrophoresis (SDS - PAGE) and densitometry. Four MHC isoforms (1,2A, 2X and a fourth isoform, provisionally called L) and five MLC isoforms (MLC1s, MLC1f, MLC3f, MLC2f, MLC2s) were identified. The major findings of this study were: (1) fast MHC isoforms (in particular MHC-2A) and fast fibres were predominant, (2) one-third of the fibres were mixed or hybrid, i.e. expressed more than one MHC isoform, (3) V0 and P0 values were determined by the MHC isoform composition and mixed fibres showed functional properties which were intermediate between pure fibres; MHC-L was associated with V0 values similar to those of MHC-2A, (4) compared with limb muscles, V0 values of laryngeal fibres were similar to those of limb muscle fibres containing the same MHC isoform whereas P0 values were lower for slow and fast 2X fibres and similar for fibres expressing MHC-2A.
AB - In the present study we aimed to determine the functional properties and the myosin heavy chain (MHC) isoform composition of single chemically skinned fibres from the vocal muscle of four adult men (age: 55-67 years). Single fibres, dissected from the bioptic samples, were chemically skinned and isometric tension (P0) and maximal shortening velocity (V0) were measured at pCa 4.6. MHC and myosin light chain (MLC) composition of fibre segments and MHC distribution of the biopsy samples were analysed by SDS-poly-acrylamide gel electrophoresis (SDS - PAGE) and densitometry. Four MHC isoforms (1,2A, 2X and a fourth isoform, provisionally called L) and five MLC isoforms (MLC1s, MLC1f, MLC3f, MLC2f, MLC2s) were identified. The major findings of this study were: (1) fast MHC isoforms (in particular MHC-2A) and fast fibres were predominant, (2) one-third of the fibres were mixed or hybrid, i.e. expressed more than one MHC isoform, (3) V0 and P0 values were determined by the MHC isoform composition and mixed fibres showed functional properties which were intermediate between pure fibres; MHC-L was associated with V0 values similar to those of MHC-2A, (4) compared with limb muscles, V0 values of laryngeal fibres were similar to those of limb muscle fibres containing the same MHC isoform whereas P0 values were lower for slow and fast 2X fibres and similar for fibres expressing MHC-2A.
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UR - http://www.scopus.com/inward/citedby.url?scp=1842835681&partnerID=8YFLogxK
U2 - 10.1023/A:1020963021105
DO - 10.1023/A:1020963021105
M3 - Article
C2 - 12500898
AN - SCOPUS:1842835681
VL - 23
SP - 187
EP - 195
JO - Journal of Muscle Research and Cell Motility
JF - Journal of Muscle Research and Cell Motility
SN - 0142-4319
IS - 3
ER -