Biomaterial Database

Unloaded shortening velocity and myosin heavy chain and alkali light chain isoform composition in rat skeletal muscle fibres. 1994

R Bottinelli, and R Betto, and S Schiaffino, and C Reggiani

Institute of Human Physiology, Pavia, Italy.

1. This study aims to assess the role of myosin heavy chain (MHC) and alkali myosin light chain (MLC) isoforms in determining maximum velocity of shortening in fast skeletal muscle fibres. 2. The maximum velocity of shortening as determined by the slack test (Vo) was tested for its relationship with MHC composition and with alkali MLC isoform ratio of fast fibres of known MHC composition. 3. MHC isoform composition was determined using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and monoclonal antibodies against MHCs, and combining the results obtained using the two methods. Three groups of fast fibres containing only one MHC isoform were identified: IIA, IIX and IIB fibres containing respectively IIA MHC, IIX MHC and IIB MHC. Fibres containing more than one MHC isoform were discarded. 4. The mean Vo value of IIA fibres was 2.33 +/- 0.29 muscle lengths per second (L s-1; mean +/- S.D.), this was significantly lower than that for IIX fibres (3.07 +/- 0.70 L s-1) which in turn had a mean Vo value significantly lower than that for IIB fibres (3.69 +/- 1.01 L s-1). 5. The relative proportion of alkali MLC isoforms (MLC3f, MLC1f) was determined by means of electrophoretic separation and densitometric quantification and was expressed as MLC3f/MLC2f with reference to the dithio-nitrobenzoic acid (DTNB) light chain (MLC2f). The mean value of the MLC3f/MLC2f ratio was significantly lower in IIA than in IIX and IIB fibres. 6. Vo was found to be proportional to the relative content of MLC3f in IIA, IIX and IIB fibres.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D007150	Immunohistochemistry	Histochemical localization of immunoreactive substances using labeled antibodies as reagents.	Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
D007536	Isomerism	The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)	Isomerisms
D008297	Male		Males
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000911	Antibodies, Monoclonal	Antibodies produced by a single clone of cells.	Monoclonal Antibodies,Monoclonal Antibody,Antibody, Monoclonal
D015879	Myosin Subfragments	Parts of the myosin molecule resulting from cleavage by proteolytic enzymes (PAPAIN; TRYPSIN; or CHYMOTRYPSIN) at well-localized regions. Study of these isolated fragments helps to delineate the functional roles of different parts of myosin. Two of the most common subfragments are myosin S-1 and myosin S-2. S-1 contains the heads of the heavy chains plus the light chains and S-2 contains part of the double-stranded, alpha-helical, heavy chain tail (myosin rod).	Actomyosin Subfragments,Meromyosin Subfragments,Myosin Rod,Myosin S-1,Myosin S-2,ATPase, Actin-S1,Actin S1 ATPase,Actoheavy Meromyosin,Actomyosin Subfragment 1 ATPase,H-Meromyosin,Heavy Meromyosin,Heavy Meromyosin Subfragment-1,Heavy Meromyosin Subfragment-2,Light Meromyosin,Myosin Subfragment-1,Myosin Subfragment-2,ATPase, Actin S1,Actin-S1 ATPase,H Meromyosin,Heavy Meromyosin Subfragment 1,Heavy Meromyosin Subfragment 2,Meromyosin Subfragment-1, Heavy,Meromyosin Subfragment-2, Heavy,Meromyosin, Actoheavy,Meromyosin, Heavy,Meromyosin, Light,Myosin S 1,Myosin S 2,Myosin Subfragment 1,Myosin Subfragment 2,Subfragment-1, Heavy Meromyosin,Subfragment-1, Myosin,Subfragment-2, Heavy Meromyosin,Subfragment-2, Myosin,Subfragments, Actomyosin,Subfragments, Meromyosin,Subfragments, Myosin
D017208	Rats, Wistar	A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.	Wistar Rat,Rat, Wistar,Wistar Rats
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus