Jennifer Rodriguez - Academia.edu (original) (raw)
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Hajee Mohammad Danesh Science & Technolgy University, Bangladesh
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Papers by Jennifer Rodriguez
Journal of Biological Chemistry, 2003
The repolarization phase of cardiac action potential is prone to aberrant excitation that is comm... more The repolarization phase of cardiac action potential is prone to aberrant excitation that is common in cardiac patients. Here, we demonstrate that this phase is markedly sensitive to Ca 2؉ because of the surprising existence of a Ca 2؉-activated K ؉ currents in cardiac cells. The current was revealed using recording conditions that preserved endogenous Ca 2؉ buffers. The Ca 2؉-activated K ؉ current is expressed differentially in atria compared with ventricles. Because of the significant contribution of the current toward membrane repolarization in cardiac myocytes, alterations of the current magnitude precipitate abnormal action potential profiles. We confirmed the presence of a small conductance Ca 2؉-activated K ؉ channel subtype (SK2) in human and mouse cardiac myocytes using Western blot analysis and reverse transcription-polymerase chain reaction and have cloned SK2 channels from human atria, mouse atria, and ventricles. Because of the marked differential expression of SK2 channels in the heart, specific ligands for Ca 2؉-activated K ؉ currents may offer a unique therapeutic opportunity to modify atrial cells without interfering with ventricular myocytes. Cardiac action potentials (APs) 1 are shaped predominantly by the interplay between transient inward Na ϩ , Ca 2ϩ , and outward K ϩ currents (1). While the repolarization phase of the AP can be wrought by the kinetics of the principal currents, small and sustained outward currents also define this phase, rendering this region prone to irregular membrane excitation.
Journal of Biological Chemistry, 2003
The repolarization phase of cardiac action potential is prone to aberrant excitation that is comm... more The repolarization phase of cardiac action potential is prone to aberrant excitation that is common in cardiac patients. Here, we demonstrate that this phase is markedly sensitive to Ca 2؉ because of the surprising existence of a Ca 2؉-activated K ؉ currents in cardiac cells. The current was revealed using recording conditions that preserved endogenous Ca 2؉ buffers. The Ca 2؉-activated K ؉ current is expressed differentially in atria compared with ventricles. Because of the significant contribution of the current toward membrane repolarization in cardiac myocytes, alterations of the current magnitude precipitate abnormal action potential profiles. We confirmed the presence of a small conductance Ca 2؉-activated K ؉ channel subtype (SK2) in human and mouse cardiac myocytes using Western blot analysis and reverse transcription-polymerase chain reaction and have cloned SK2 channels from human atria, mouse atria, and ventricles. Because of the marked differential expression of SK2 channels in the heart, specific ligands for Ca 2؉-activated K ؉ currents may offer a unique therapeutic opportunity to modify atrial cells without interfering with ventricular myocytes. Cardiac action potentials (APs) 1 are shaped predominantly by the interplay between transient inward Na ϩ , Ca 2ϩ , and outward K ϩ currents (1). While the repolarization phase of the AP can be wrought by the kinetics of the principal currents, small and sustained outward currents also define this phase, rendering this region prone to irregular membrane excitation.