Chloride channels in myotonia congenita assessed by velocity recovery cycles


Autoria(s): Tan, S. Veronica; Z'Graggen, Werner Josef; Boërio, Delphine; Rayan, Dipa Raja; Norwood, Fiona; Ruddy, Deborah; Howard, R.; Hanna, Michael G.; Bostock, Hugh
Data(s)

01/06/2014

Resumo

Introduction: Myotonia congenita (MC) is caused by congenital defects in the muscle chloride channel CLC-1. This study used muscle velocity recovery cycles (MVRCs) to investigate how membrane function is affected. Methods: MVRCs and responses to repetitive stimulation were compared between 18 patients with genetically confirmed MC (13 recessive, 7 dominant) and 30 age-matched normal controls. Results: MC patients exhibited increased early supernormality, but treatment with sodium channel blockers prevented this. After multiple conditioning stimuli, late supernormality was enhanced in all MC patients, indicating delayed repolarization. These abnormalities were similar between the MC subtypes, but recessive patients showed a greater drop in amplitude during repetitive stimulation. Discussion: MVRCs indicate that chloride conductance only becomes important when muscle fibers are depolarized. The differential responses to repetitive stimulation suggest that in dominant MC the affected chloride channels are activated by strong depolarization, consistent with a positive shift of the CLC-1 activation curve. © 2013 Wiley Periodicals, Inc.

Formato

application/pdf

Identificador

http://boris.unibe.ch/44494/1/TAn2013_MuscleNerve.pdf

Tan, S. Veronica; Z'Graggen, Werner Josef; Boërio, Delphine; Rayan, Dipa Raja; Norwood, Fiona; Ruddy, Deborah; Howard, R.; Hanna, Michael G.; Bostock, Hugh (2014). Chloride channels in myotonia congenita assessed by velocity recovery cycles. Muscle & nerve, 49(6), pp. 845-857. John Wiley & Sons 10.1002/mus.24069 <http://dx.doi.org/10.1002/mus.24069>

doi:10.7892/boris.44494

info:doi:10.1002/mus.24069

info:pmid:24037712

urn:issn:0148-639X

Idioma(s)

eng

Publicador

John Wiley & Sons

Relação

http://boris.unibe.ch/44494/

Direitos

info:eu-repo/semantics/openAccess

Fonte

Tan, S. Veronica; Z'Graggen, Werner Josef; Boërio, Delphine; Rayan, Dipa Raja; Norwood, Fiona; Ruddy, Deborah; Howard, R.; Hanna, Michael G.; Bostock, Hugh (2014). Chloride channels in myotonia congenita assessed by velocity recovery cycles. Muscle & nerve, 49(6), pp. 845-857. John Wiley & Sons 10.1002/mus.24069 <http://dx.doi.org/10.1002/mus.24069>

Palavras-Chave #610 Medicine & health
Tipo

info:eu-repo/semantics/article

info:eu-repo/semantics/publishedVersion

PeerReviewed