A modified local control model for Ca2+ transients in cardiomyocytes: junctional flux is accompanied by release from adjacent non-junctional RyRs.

ABSTRACT: Excitation-contraction coupling in cardiomyocytes requires Ca(2+) influx through dihydropyridine receptors in the sarcolemma, which gates Ca(2+) release through sarcoplasmic ryanodine receptors (RyRs). Ca(2+) influx, release and diffusion produce a cytosolic Ca(2+) transient. Here, we investigated the relationship between Ca(2+) transients and the spatial arrangement of the sarcolemma including the transverse tubular system (t-system). To accomplish this, we studied isolated ventricular myocytes of rabbit, which exhibit a heterogeneously distributed t-system. We developed protocols for fluorescent labeling and triggered two-dimensional confocal microscopic imaging with high spatiotemporal resolution. From sequences of microscopic images, we measured maximal upstroke velocities and onset ti

SUBMITTER: Torres NS 

PROVIDER: S-EPMC3942534 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature