Modulation by caffeine of calcium-release microdomains in frog skeletal muscle fibers
Biol. Res
;
39(3): 567-581, 2006. ilus
Article
in English
| 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.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Caffeine
/
Calcium
/
Muscle, Skeletal
/
Muscle Fibers, Skeletal
/
Central Nervous System Stimulants
/
Muscle Contraction
Limits:
Animals
Language:
English
Journal:
Biol. Res
Journal subject:
Biology
Year:
2006
Type:
Article
/
Project document
Affiliation country:
United States
Institution/Affiliation country:
University of California/US
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