Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats.

Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats. Abstract Text:

H Zhong,R R Roy,J Woo,J A Kim,V R Edgerton,

The effects of chronic neuromuscular inactivity on the phenotype and size of muscle fibres in a fast ankle extensor (medial gastrocnemius, MG) and a fast ankle flexor (tibialis anterior, TA) muscle of the rat hindlimb were determined. Inactivity was produced by spinal cord isolation (SI), i.e. complete spinal cord transections at a mid-thoracic and high sacral level and bilateral deafferentation between the transection sites. After 90 days of SI, the MG and TA muscle weights were 53 and 45% lower than in age-matched controls. Overall mean fibre sizes in the deep (close to the bone) and superficial (away from the bone) regions were approximately 60 and 65% smaller in the MG and approximately 40 and 50% smaller in the TA of SI than control rats, respectively. The myosin heavy chain (MHC) composition shifted towards the faster isoforms after SI: the MG showed an increase in both types IIx (20%) and IIb (23%), whereas the TA showed a marked increase in type IIx (94%) and a decrease in type IIb (18%) MHC. Both muscles in SI rats showed no type IIa and only one MG muscle had approximately 5% type I MHC. These results show that prolonged inactivity has a stronger effect on a fast extensor compared with a fast flexor in the rat hindlimb. The larger decrease in mass and fibre size in the MG than the TA most probably reflects the larger impact of chronic inactivity on the normally more highly recruited extensor than flexor muscle. The primary shift to type IIb MHC in the MG and type IIx MHC in the TA indicate a different default mode for an inactive extensor vs. flexor muscle, and may reflect differing activity-independent neural influences, i.e. neurotrophic factors, on muscle fibre phenotype in extensors vs. flexors.

Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats. Publishing Authors By Initials

H Zhong,RR Roy,J Woo,JA Kim,VR Edgerton,

For similar natural sciences: time research abstracts see: natural sciences: time research

PUBMED ID PMID:

MEDLINE DATE:

Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats. Journal Published:

PUBLICATION TYPE: Research Support, N.I.H., Extr

Journal: Journal of anatomy

VOLUME: 210

Page Numbers: 19-31

Journal Abbreviation: J. Anat.

ISSN: 0021-8782

DAY: 3

MONTH: Jan

YEAR: 2007

Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 137162

Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats. Keywords Mesh Terms:

KEYWORDS: Time

MESH TERMS: metabolism

Chemical & Substance for Abstract: Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats. Information

Substance Name: Protein Isoforms

Registry Number: 0

Grant and Affiliation Information for Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats.

AFFILIATION: Brain Research Institute, Department of Physiological Science, University of California Los Angeles 90095-1761, USA.

Country: England

AGENCY: United States NINDS

GRANT: NS16333

ACRONYM: NS

MEDLINETA: J Anat

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats Related Publications

• A multiple-electrode cochlear implant.
• Abnormal vaginal bleeding.
• Acute effects of exercise on MR imaging of skeletal muscle: concentric vs eccentric actions.
• Customers are more than consumers. Realize the value of marketing to EMTs.
• Differential modulation of myosin heavy chain phenotype in an inactive extensor and flexor muscle of adult rats.
• Effect of clomiphene citrate on pituitary responsiveness to gonadotropin releasing hormone in rams and wethers.
• Effects of season and lactation on luteinizing hormone secretion in postpartum ewes.
• Electromechanical stimulation ameliorates inactivity-induced adaptations in the medial gastrocnemius of adult rats.
• Epidural spinal cord stimulation plus quipazine administration enable stepping in complete spinal adult rats.
• Epidural stimulation: Comparison of the spinal circuits that generate and control locomotion in rats, cats and humans.
• Flexor bias of joint position in humans during spaceflight.
• Focus groups can help drive patient satisfaction.
• Genetically engineered human salivary histatin genes are functional in Candida albicans: development of a new system for studying histatin candidacidal activity.
• Histatin 5 initiates osmotic stress response in Candida albicans via activation of the Hog1 mitogen-activated protein kinase pathway.
• Insulin action on the liver in vivo.
• Irradiation as a causative factor in thyroid cancer.
• Is spinal cord isolation a good model of muscle disuse?
• Plasticity of functional connectivity in the adult spinal cord.
• Proceedings: Rehabilitation of the oral cavity by plastic surgery after cancer resections.
• Psychoelectric measurements and results from cochlear implant patients.
• Public Health Applications of High-Speed Photography.
• Rat alpha- and gamma-motoneuron soma size and succinate dehydrogenase activity are independent of neuromuscular activity level.
• Reconstruction of the hypopharynx and the cervical esophagus after removal of cancer.
• Released ATP is an extracellular cytotoxic mediator in salivary histatin 5-induced killing of Candida albicans.
• Removal of swine zonae pellucidae with sequential exposures to pronase and acidified medium.
• Spinal cord reflexes induced by epidural spinal cord stimulation in normal awake rats.
• The P-113 Fragment of Histatin 5 Requires a Specific Peptide Sequence for Intracellular Translocation in Candida albicans, Which Is Independent of Cell Wall Binding.
• The Role of Muscle Activity in Health Maintenance for Spinal Cord Injury Patients: 298: 9:20 AM-9:45 AM.
• The role of low-dosage irradiation in selected cases of menstrual disorders.
• Tools for understanding and optimizing robotic gait training.