"P(GP204/02/D129), Z(AV0Z2076919)" . "The majority of trans-sarcolemmal Ca2+ flux occurs across the t-tubule membrane, which therefore plays a key role in cardiac excitation-contraction coupling; however Ca2+ within the t-tubules does not equilibrate instantaneously with the bulk extracellular solution. Thus, during activity, changes in [Ca2+] may occur within the t-tubule lumen, which would, in turn, alter trans-sarcolemmal Ca2+ flux. To test this hypothesis, we used a computer model of rat ventricular myocyte including a t-tubular system. The action potentials in the two membranes were not significantly different, reflecting the electrical coupling of the two compartments. However, [Ca2+] within the t-tubule lumen decreased on each stimulus, and decreased cumulatively, until reaching a new dynamic steady state, with increasing stimulation rate. These data suggest that activity-dependent depletion of Ca2+ within the t-tubule lumen, adjacent to the trans-sarcolemmal Ca2+ flux pathways, decreases the Ca load, and hence lowers the inotropic"@en . . . "\u0160imurda, Ji\u0159\u00ED" . "Zm\u011Bny [Ca2+] uvnit\u0159 t-tubul\u016F mohou m\u011Bnit inotropn\u00ED stav srde\u010Dn\u00EDch ventrikul\u00E1rn\u00EDch bun\u011Bk potkana"@cs . "The majority of trans-sarcolemmal Ca2+ flux occurs across the t-tubule membrane, which therefore plays a key role in cardiac excitation-contraction coupling; however Ca2+ within the t-tubules does not equilibrate instantaneously with the bulk extracellular solution. Thus, during activity, changes in [Ca2+] may occur within the t-tubule lumen, which would, in turn, alter trans-sarcolemmal Ca2+ flux. To test this hypothesis, we used a computer model of rat ventricular myocyte including a t-tubular system. The action potentials in the two membranes were not significantly different, reflecting the electrical coupling of the two compartments. However, [Ca2+] within the t-tubule lumen decreased on each stimulus, and decreased cumulatively, until reaching a new dynamic steady state, with increasing stimulation rate. These data suggest that activity-dependent depletion of Ca2+ within the t-tubule lumen, adjacent to the trans-sarcolemmal Ca2+ flux pathways, decreases the Ca load, and hence lowers the inotropic" . "Proceedings of The Physiological Society" . "Zm\u011Bny [Ca2+] uvnit\u0159 t-tubul\u016F mohou m\u011Bnit inotropn\u00ED stav srde\u010Dn\u00EDch ventrikul\u00E1rn\u00EDch bun\u011Bk potkana"@cs . "RIV/00216224:14110/04:00011947" . "Orchard, Clive" . "RIV/00216224:14110/04:00011947!RIV09-GA0-14110___" . . . . "P\u00E1sek, Michal" . "Changes of [Ca2+] in the t-tubule lumen during activity may modulate the inotropic state of rat cardiac ventricular myocytes"@en . . . "Pr\u00E1ce prezentuje v\u00FDsledky simulac\u00ED na modelu srde\u010Dn\u00ED komorov\u00E9 bu\u0148ky potkana ukazuj\u00EDc\u00ED vliv koncentra\u010Dn\u00EDch zm\u011Bn tubul\u00E1rn\u00EDch iont\u016F Ca2+ (b\u011Bhem bun\u011B\u010Dn\u00E9 aktivity) na intracelul\u00E1rn\u00ED v\u00E1pn\u00EDkovou rovnov\u00E1hu a inotropn\u00ED stav komorov\u00FDch bun\u011Bk."@cs . "2"^^ . "4"^^ . "University of Oxford" . . "Changes of [Ca2+] in the t-tubule lumen during activity may modulate the inotropic state of rat cardiac ventricular myocytes" . "cardiac cell inotropy; tubular system; quantitative modelling"@en . "Oxford" . . "Oxford" . . "2004-11-01+01:00"^^ . . "Changes of [Ca2+] in the t-tubule lumen during activity may modulate the inotropic state of rat cardiac ventricular myocytes"@en . . . . "Christ\u00E9, Georges" . "[7EDC010B18FD]" . . "Changes of [Ca2+] in the t-tubule lumen during activity may modulate the inotropic state of rat cardiac ventricular myocytes" . . . "557331" . . "1"^^ . . "14110" .