Effects of Calcium Channel Antagonists on Ca2+Transients in Rat and Canine Cardiomyocytes

Hensley, James; Ge, Billman; Jd, Johnson; Cm, Hohl; Ra, Altschuld

doi:10.1006/jmcc.1996.0348

Cited by 21 publications

(11 citation statements)

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“…We found that the calcium channel blocker amlodipine decreased the amplitude of ca 2+ transients in d7cMs and d21cMs in a similar fashion to the response in primary cardiomyocytes 9 ( Fig. 4A).…”

Section: Relationship Between Ion Channels and Contractile Functionsupporting

confidence: 60%

Gene Expression Profiling of Functional Murine Embryonic Stem Cell-Derived Cardiomyocytes and Comparison with Adult Heart: Profiling of Murine ESC-Derived Cardiomyocytes

et al. 2009

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although embryonic stem cell (esc)-derived cardiomyocytes may be a powerful tool in drug discovery, their potential has not yet been fully explored. nor has a detailed comparison with adult heart tissue been performed. We have developed a method for efficient production of cardiomyocyte-rich embryoid bodies (eBs) from murine escs. analysis of global gene expression profiles showed that eBs on day 7 and/or 21 of differentiation (d7cMs and d21cMs, respectively) were similar to adult heart tissue for genes categorized as regulators of muscle contraction or voltage-gated ion channel activity, although d21cMs were more mature than d7cMs for contractile components related to morphological structures. calcium and sodium channel blockers altered ca 2+ transients, and isoproterenol, a β-adrenergic compound, increased the rate of beating in d7cMs and d21cMs. our gene analytic system therefore enabled us to identify genes that are expressed in the physiological pathways associated with ion channels and structural components in d7cMs and d21cMs. We conclude that eBs might be of use for the basic screening of drugs that might affect contractile function through ion channels. (Journal of Biomolecular

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Section: Relationship Between Ion Channels and Contractile Functionsupporting

confidence: 60%

Gene Expression Profiling of Functional Murine Embryonic Stem Cell-Derived Cardiomyocytes and Comparison with Adult Heart: Profiling of Murine ESC-Derived Cardiomyocytes

et al. 2009

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“…Cardiac myocyte shortening measurements were done as described earlier [22] using an IonOptix system. The myocytes were placed in a perfusion chamber on an inverted microscope stage in Krebs-Henseleit (K-H) solution containing (in mmol/L) 120 NaCl, 4.7 KCl, 0.94 MgSO 4 , 1.2 KH 2 PO 4 , 25 NaHCO 3 , 11.5 Glucose and 0.1 ascorbate, preoxygenated with 95% O 2 /5% CO 2 with 1 mM Ca 2+ .…”

Section: Myocyte Shortening Measurementsmentioning

confidence: 99%

Overexpression of sarcolipin decreases myocyte contractility and calcium transient

Babu¹,

Zheng²,

Natarajan³

et al. 2005

Cardiovascular Research

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“…Blockade of Ltype sarcolemmal calcium channels by verapamil diminishes the amplitude of the myocardial calcium transient (9) and thereby decreases the contractile state. Less well recognized is the fact that verapamil may reduce diastolic intracellular calcium concentration (14,23).…”

Section: Discussionmentioning

confidence: 99%

A common mechanism for concurrent changes of diastolic muscle length and systolic function in intact hearts

Zhu

et al. 2001

American Journal of Physiology-Heart and Circulatory Physiology

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Mechanical properties of the myocardium at end diastole have been thought to be dominated by passive material properties rather than by active sarcomere cross-bridge interactions. This study tested the hypothesis that residual cross-bridges significantly contribute to end-diastolic mechanics in vivo and that changes in end-diastolic cross-bridge interaction parallel concurrent changes in systolic cross-bridge interaction. Open-chest anesthetized pigs were treated with intracoronary verapamil (n = 7) or 2,3-butanedione monoxime (BDM; n = 8). Regional left ventricular external work and end-diastolic pressure (EDP) versus end-diastolic segment length (EDL) relations were determined in the treated and untreated regions of each heart. Both agents reduced external work of treated regions to 31-38% of baseline and concurrently shifted EDP versus EDL relations to the right (i.e., greater EDL at a given EDP) by an average of 5% (P < 0.05). During washout of the drugs, EDP versus EDL returned to baseline in parallel with recovery of external work. Sarcomere length, measured by transmission electron microscopy in BDM-treated and untreated regions of the same hearts after diastolic arrest and perfusion fixation, was 8% greater in BDM-treated regions (P < 0.01). We concluded that residual diastolic cross-bridges significantly and reversibly influence end-diastolic mechanics in vivo. Alterations of end-diastolic and systolic cross-bridge interactions occur in parallel. Keywordsdiastole; ventricular function; calcium channel blockers; di-acetyl analogs and derivatives; sarcomeres Cross-bridge cycling triggered by the presence of cytosolic calcium is the basis for force generation in muscle. In systole, the cross-bridge cycling rate and force generation increase in relation to the magnitude of the cytosolic calcium transient and the sensitivity of myofibrillar regulatory proteins to calcium (8). In diastole, there is an active reuptake of calcium into the sarcoplasmic reticulum; however, a low level of calcium-activated crossbridge cycling and active tension development may persist at end diastole (17). Thus, whereas end-diastolic ventricular pressure-dimension relations are generally considered to reflect the underlying passive material properties of cardiac muscle (13), it is possible that changes in calcium availability or myofilament calcium sensitivity influence these relations. This concept is supported by a study (5) in isolated spontaneously beating cardiac myocytes demonstrating that cell length continues to increase throughout diastole. It is also supported by studies (12,19) Recent data from our laboratory support such a prediction. In a porcine model of acute myocardial ischemia and reperfusion resulting in systolic dysfunction (stunning), we observed increased end-diastolic segment length (EDL) at low EDP in vivo and increased diastolic sarcomere length after in situ perfusion fixation at low LV cavity pressure (15). These increases in end-diastolic muscle length and diastolic sarcomere length occurred in ...

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Effects of Calcium Channel Antagonists on Ca2+Transients in Rat and Canine Cardiomyocytes

Cited by 21 publications

References 0 publications

Gene Expression Profiling of Functional Murine Embryonic Stem Cell-Derived Cardiomyocytes and Comparison with Adult Heart: Profiling of Murine ESC-Derived Cardiomyocytes

Gene Expression Profiling of Functional Murine Embryonic Stem Cell-Derived Cardiomyocytes and Comparison with Adult Heart: Profiling of Murine ESC-Derived Cardiomyocytes

Overexpression of sarcolipin decreases myocyte contractility and calcium transient

A common mechanism for concurrent changes of diastolic muscle length and systolic function in intact hearts

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