Matches in SemOpenAlex for { <https://semopenalex.org/work/W3205767593> ?p ?o ?g. }
- W3205767593 endingPage "794" @default.
- W3205767593 startingPage "794" @default.
- W3205767593 abstract "Cardiac alternans is characterized by alternating weak and strong beats of the heart. This signaling at the cellular level may appear as alternating long and short action potentials (APs) that occur in synchrony with alternating large and small calcium transients, respectively. Previous studies have suggested that alternans manifests itself through either a voltage dependent mechanism based upon action potential restitution or as a calcium dependent mechanism based on refractoriness of calcium release. We use a novel model of cardiac excitation-contraction (EC) coupling in the rat ventricular myocyte that includes 20,000 calcium release units (CRU) each with 49 ryanodine receptors (RyR2s) and 7 L-type calcium channels that are all stochastically gated. The model suggests that at the cellular level in the case of alternans produced by rapid pacing, the mechanism requires a synergy of voltage- and calcium-dependent mechanisms. The rapid pacing reduces AP duration and magnitude reducing the number of L-type calcium channels activating individual CRUs during each AP and thus increases the population of CRUs that can be recruited stochastically. Elevated myoplasmic and sarcoplasmic reticulum (SR) calcium, [Ca2+]myo and [Ca2+]SR respectively, increases ryanodine receptor open probability (Po) according to our model used in this simulation and this increased the probability of activating additional CRUs. A CRU that opens in one beat is less likely to open the subsequent beat due to refractoriness caused by incomplete refilling of the junctional sarcoplasmic reticulum (jSR). Furthermore, the model includes estimates of changes in Na+ fluxes and [Na+]i and thus provides insight into how changes in electrical activity, [Na+]i and sodium-calcium exchanger activity can modulate alternans. The model thus tracks critical elements that can account for rate-dependent changes in [Na+]i and [Ca2+]myo and how they contribute to the generation of Ca2+ signaling alternans in the heart." @default.
- W3205767593 created "2021-10-25" @default.
- W3205767593 creator A5000970293 @default.
- W3205767593 creator A5055899029 @default.
- W3205767593 creator A5057408420 @default.
- W3205767593 creator A5060993669 @default.
- W3205767593 date "2021-10-18" @default.
- W3205767593 modified "2023-10-17" @default.
- W3205767593 title "Cardiac Alternans Occurs through the Synergy of Voltage- and Calcium-Dependent Mechanisms" @default.
- W3205767593 cites W1538188928 @default.
- W3205767593 cites W1630816364 @default.
- W3205767593 cites W1963862937 @default.
- W3205767593 cites W1965371036 @default.
- W3205767593 cites W1966745421 @default.
- W3205767593 cites W1971676339 @default.
- W3205767593 cites W1973754863 @default.
- W3205767593 cites W1974171267 @default.
- W3205767593 cites W1975641338 @default.
- W3205767593 cites W1977643020 @default.
- W3205767593 cites W1979207635 @default.
- W3205767593 cites W1983707293 @default.
- W3205767593 cites W1985578759 @default.
- W3205767593 cites W1985940938 @default.
- W3205767593 cites W1988382203 @default.
- W3205767593 cites W1990406674 @default.
- W3205767593 cites W1991182597 @default.
- W3205767593 cites W1991928518 @default.
- W3205767593 cites W1992091268 @default.
- W3205767593 cites W1994348876 @default.
- W3205767593 cites W1995946312 @default.
- W3205767593 cites W1996382853 @default.
- W3205767593 cites W2000683352 @default.
- W3205767593 cites W2005865511 @default.
- W3205767593 cites W2008864455 @default.
- W3205767593 cites W2012544852 @default.
- W3205767593 cites W2013123418 @default.
- W3205767593 cites W2013157031 @default.
- W3205767593 cites W2023229013 @default.
- W3205767593 cites W2027228752 @default.
- W3205767593 cites W2027296825 @default.
- W3205767593 cites W2028146834 @default.
- W3205767593 cites W2029620282 @default.
- W3205767593 cites W2031053544 @default.
- W3205767593 cites W2034214746 @default.
- W3205767593 cites W2037899064 @default.
- W3205767593 cites W2039411714 @default.
- W3205767593 cites W2040165826 @default.
- W3205767593 cites W2045529347 @default.
- W3205767593 cites W2047233785 @default.
- W3205767593 cites W2050553914 @default.
- W3205767593 cites W2050584736 @default.
- W3205767593 cites W2050824263 @default.
- W3205767593 cites W2054225000 @default.
- W3205767593 cites W2055098453 @default.
- W3205767593 cites W2055385895 @default.
- W3205767593 cites W2061535052 @default.
- W3205767593 cites W2061906053 @default.
- W3205767593 cites W2067275294 @default.
- W3205767593 cites W2067640311 @default.
- W3205767593 cites W2076405436 @default.
- W3205767593 cites W2077129671 @default.
- W3205767593 cites W2080484314 @default.
- W3205767593 cites W2082967245 @default.
- W3205767593 cites W2086871275 @default.
- W3205767593 cites W2087532247 @default.
- W3205767593 cites W2088020365 @default.
- W3205767593 cites W2100807528 @default.
- W3205767593 cites W2101417788 @default.
- W3205767593 cites W2101482473 @default.
- W3205767593 cites W2102311103 @default.
- W3205767593 cites W2105458107 @default.
- W3205767593 cites W2106876658 @default.
- W3205767593 cites W2110276869 @default.
- W3205767593 cites W2111952367 @default.
- W3205767593 cites W2112713043 @default.
- W3205767593 cites W2117765582 @default.
- W3205767593 cites W2120566104 @default.
- W3205767593 cites W2131435989 @default.
- W3205767593 cites W2132561989 @default.
- W3205767593 cites W2135454160 @default.
- W3205767593 cites W2137974601 @default.
- W3205767593 cites W2139124958 @default.
- W3205767593 cites W2140396009 @default.
- W3205767593 cites W2142108688 @default.
- W3205767593 cites W2145264435 @default.
- W3205767593 cites W2145563296 @default.
- W3205767593 cites W2147142035 @default.
- W3205767593 cites W2147537230 @default.
- W3205767593 cites W2148734617 @default.
- W3205767593 cites W2150962221 @default.
- W3205767593 cites W2153042674 @default.
- W3205767593 cites W2153503204 @default.
- W3205767593 cites W2159258890 @default.
- W3205767593 cites W2161645439 @default.
- W3205767593 cites W2166325927 @default.
- W3205767593 cites W2170271247 @default.
- W3205767593 cites W2171183321 @default.
- W3205767593 cites W2299045777 @default.