Modulation by caffeine of calcium-release microdomains in frog skeletal muscle fibers
Biol. Res
;
39(3): 567-581, 2006. ilus
Artigo
em Inglês
| LILACS
| ID: lil-437388
ABSTRACT
The effects of caffeine on the process of excitation-contraction coupling in amphibian skeletal muscle fibers were investigated using the confocal spot detection technique. This method permits to carefully discriminate between caffeine effects on the primary sources of Ca2+ release at the Z-lines where the triads are located and secondary actions on other potential Ca Release sources. Our results demonstrate that 0.5 mM caffeine potentiates and prolongs localized action-potential evoked Ca2+ transients recorded at the level of the Z-lines, but that 1mM only prolongs them. The effects at both doses are reversible. At the level of the M-line, localized Ca2+ transients displayed more variability in the presence of 1 mM caffeine than in control conditions. At this dose of caffeine, extra-junctional sources of Ca2+ release also were observed occasionally.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Cafeína
/
Cálcio
/
Músculo Esquelético
/
Fibras Musculares Esqueléticas
/
Estimulantes do Sistema Nervoso Central
/
Contração Muscular
Limite:
Animais
Idioma:
Inglês
Revista:
Biol. Res
Assunto da revista:
Biologia
Ano de publicação:
2006
Tipo de documento:
Artigo
/
Documento de projeto
País de afiliação:
Estados Unidos
Instituição/País de afiliação:
University of California/US
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