SciELO - Scientific Electronic Library Online

 
vol.39 issue3Increased expression of SNARE proteins and synaptotagmin IV in islets from pregnant rats and in vitro prolactin-treated neonatal islets author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Biological Research

Print version ISSN 0716-9760

Abstract

VERGARA, JULIO L  and  DIFRANCO, MARINO. Modulation by caffeine of calcium-release microdomains in frog skeletal muscle fibers. Biol. Res. [online]. 2006, vol.39, n.3, pp.567-581. ISSN 0716-9760.  http://dx.doi.org/10.4067/S0716-97602006000300017.

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.

Keywords : excitation-contraction coupling; caffeine; confocal spot detection; calcium transients; frog skeletal muscle; calcium microdomains.

        · text in English     · English ( pdf )

 

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License