Kinetics on Demand Is a Simple Mathematical Solution that Fits Recorded Caffeine-Induced Luminal SR Ca2 Changes in Smooth Muscle CellsReportar como inadecuado




Kinetics on Demand Is a Simple Mathematical Solution that Fits Recorded Caffeine-Induced Luminal SR Ca2 Changes in Smooth Muscle Cells - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

The process of Ca2+ release from sarcoplasmic reticulum SR comprises 4 phases in smooth muscle cells. Phase 1 is characterized by a large increase of the intracellular Ca2+ concentration Ca2+i with a minimal reduction of the free luminal SR Ca2+ Ca2+FSR. Importantly, active SR Ca2+ ATPases SERCA pumps are necessary for phase 1 to occur. This situation cannot be explained by the standard kinetics that involves a fixed amount of luminal Ca2+ binding sites. A new mathematical model was developed that assumes an increasing SR Ca2+ buffering capacity in response to an increase of the luminal SR Ca2+ that is called Kinetics-on-Demand KonD model. This approach can explain both phase 1 and the refractory period associated with a recovered Ca2+FSR. Additionally, our data suggest that active SERCA pumps are a requisite for KonD to be functional; otherwise luminal SR Ca2+ binding proteins switch to standard kinetics. The importance of KonD Ca2+ binding properties is twofold: a more efficient Ca2+ release process and that Ca2+FSR and Ca2+-bound to SR proteins Ca2+BSR can be regulated separately allowing for Ca2+ release to occur provided by Ca2+-bound to luminal Ca2+ binding proteins without an initial reduction of the Ca2+FSR.



Autor: Norma C. Perez-Rosas, Norma L. Gomez-Viquez, Adan Dagnino-Acosta, Moises Santillan, Agustín Guerrero-Hernandez

Fuente: http://plos.srce.hr/



DESCARGAR PDF




Documentos relacionados