Cargando…

The relationship between ciliary neurotrophic factor (CNTF) genotype and motor unit physiology: preliminary studies

BACKGROUND: Ciliary neurotrophic factor (CNTF) is important for neuronal and muscle development, and genetic variation in the CNTF gene has been associated with muscle strength. The effect of CNTF on nerve development suggests that CNTF genotype may be associated with force production via its influe...

Descripción completa

Detalles Bibliográficos
Autores principales: Conwit, Robin A, Ling, Shari, Roth, Stephen, Stashuk, Daniel, Hurley, Ben, Ferrell, Robert, Metter, E Jeffrey
Formato: Texto
Lenguaje:English
Publicado: BioMed Central 2005
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1249585/
https://www.ncbi.nlm.nih.gov/pubmed/16181490
http://dx.doi.org/10.1186/1472-6793-5-15
_version_ 1782125720378540032
author Conwit, Robin A
Ling, Shari
Roth, Stephen
Stashuk, Daniel
Hurley, Ben
Ferrell, Robert
Metter, E Jeffrey
author_facet Conwit, Robin A
Ling, Shari
Roth, Stephen
Stashuk, Daniel
Hurley, Ben
Ferrell, Robert
Metter, E Jeffrey
author_sort Conwit, Robin A
collection PubMed
description BACKGROUND: Ciliary neurotrophic factor (CNTF) is important for neuronal and muscle development, and genetic variation in the CNTF gene has been associated with muscle strength. The effect of CNTF on nerve development suggests that CNTF genotype may be associated with force production via its influence on motor unit size and firing patterns. The purpose of this study is to examine whether CNTF genotype differentially affects motor unit activation in the vastus medialis with increasing isometric force during knee extension. RESULTS: Sixty-nine healthy subjects were genotyped for the presence of the G and A (null) alleles in the CNTF gene (n = 57 G/G, 12 G/A). They were tested using a dynamometer during submaximal isometric knee extension contractions that were from 10–50% of their maximal strength. During the contractions, the vastus medialis was studied using surface and intramuscular electromyography with spiked triggered averaging to assess surface-detected motor unit potential (SMUP) area and mean firing rates (mFR) from identified motor units. CNTF genotyping was performed using standard PCR techniques from DNA obtained from leucocytes of whole blood samples. The CNTF G/A genotype was associated with smaller SMUP area motor units and lower mFR at higher force levels, and fewer but larger units at lower force levels than G/G homozygotes. The two groups used motor units with different size and activation characteristics with increasing force generation. While G/G subjects tended to utilize larger motor units with increasing force, G/A subjects showed relatively less increase in size by using relatively larger units at lower force levels. At higher force levels, G/A subjects were able to generate more force per motor unit size suggesting more efficient motor unit function with increasing muscle force. CONCLUSION: Differential motor unit responses were observed between CNTF genotypes at force levels utilized in daily activities.
format Text
id pubmed-1249585
institution National Center for Biotechnology Information
language English
publishDate 2005
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-12495852005-10-08 The relationship between ciliary neurotrophic factor (CNTF) genotype and motor unit physiology: preliminary studies Conwit, Robin A Ling, Shari Roth, Stephen Stashuk, Daniel Hurley, Ben Ferrell, Robert Metter, E Jeffrey BMC Physiol Research Article BACKGROUND: Ciliary neurotrophic factor (CNTF) is important for neuronal and muscle development, and genetic variation in the CNTF gene has been associated with muscle strength. The effect of CNTF on nerve development suggests that CNTF genotype may be associated with force production via its influence on motor unit size and firing patterns. The purpose of this study is to examine whether CNTF genotype differentially affects motor unit activation in the vastus medialis with increasing isometric force during knee extension. RESULTS: Sixty-nine healthy subjects were genotyped for the presence of the G and A (null) alleles in the CNTF gene (n = 57 G/G, 12 G/A). They were tested using a dynamometer during submaximal isometric knee extension contractions that were from 10–50% of their maximal strength. During the contractions, the vastus medialis was studied using surface and intramuscular electromyography with spiked triggered averaging to assess surface-detected motor unit potential (SMUP) area and mean firing rates (mFR) from identified motor units. CNTF genotyping was performed using standard PCR techniques from DNA obtained from leucocytes of whole blood samples. The CNTF G/A genotype was associated with smaller SMUP area motor units and lower mFR at higher force levels, and fewer but larger units at lower force levels than G/G homozygotes. The two groups used motor units with different size and activation characteristics with increasing force generation. While G/G subjects tended to utilize larger motor units with increasing force, G/A subjects showed relatively less increase in size by using relatively larger units at lower force levels. At higher force levels, G/A subjects were able to generate more force per motor unit size suggesting more efficient motor unit function with increasing muscle force. CONCLUSION: Differential motor unit responses were observed between CNTF genotypes at force levels utilized in daily activities. BioMed Central 2005-09-23 /pmc/articles/PMC1249585/ /pubmed/16181490 http://dx.doi.org/10.1186/1472-6793-5-15 Text en Copyright © 2005 Conwit et al; licensee BioMed Central Ltd.
spellingShingle Research Article
Conwit, Robin A
Ling, Shari
Roth, Stephen
Stashuk, Daniel
Hurley, Ben
Ferrell, Robert
Metter, E Jeffrey
The relationship between ciliary neurotrophic factor (CNTF) genotype and motor unit physiology: preliminary studies
title The relationship between ciliary neurotrophic factor (CNTF) genotype and motor unit physiology: preliminary studies
title_full The relationship between ciliary neurotrophic factor (CNTF) genotype and motor unit physiology: preliminary studies
title_fullStr The relationship between ciliary neurotrophic factor (CNTF) genotype and motor unit physiology: preliminary studies
title_full_unstemmed The relationship between ciliary neurotrophic factor (CNTF) genotype and motor unit physiology: preliminary studies
title_short The relationship between ciliary neurotrophic factor (CNTF) genotype and motor unit physiology: preliminary studies
title_sort relationship between ciliary neurotrophic factor (cntf) genotype and motor unit physiology: preliminary studies
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1249585/
https://www.ncbi.nlm.nih.gov/pubmed/16181490
http://dx.doi.org/10.1186/1472-6793-5-15
work_keys_str_mv AT conwitrobina therelationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT lingshari therelationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT rothstephen therelationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT stashukdaniel therelationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT hurleyben therelationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT ferrellrobert therelationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT metterejeffrey therelationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT conwitrobina relationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT lingshari relationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT rothstephen relationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT stashukdaniel relationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT hurleyben relationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT ferrellrobert relationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies
AT metterejeffrey relationshipbetweenciliaryneurotrophicfactorcntfgenotypeandmotorunitphysiologypreliminarystudies