Abstract：
:In the present investigation, the effects of forskolin on intracellular sodium activity were studied in quiescent and electrically stimulated cardiac Purkinje fibers from sheep using Na+-sensitive microelectrodes. Also assessed, were the effects of this promoter of cytosolic cAMP production on resting membrane potential, action potential and twitch tension. In the quiescent fibers, forskolin (12 microM) caused intracellular sodium activity to decrease in the face of cellular depolarization. This cellular depolarization was occasionally accompanied by spontaneous firing of action potentials. In the stimulated fibers, forskolin (10 microM) also caused intracellular sodium activity to decrease. Moreover, it caused a marked acceleration of phase 4 pacemaker depolarization, an elevation of the plateau of the action potential and an increase in twitch tension. When the Na+ pump was inhibited by either strophanthidin (1 microM) or by 0 mM extracellular K+, forskolin had no effect on intracellular sodium activity. In summary, the results of the present study indicate that forskolin, presumably by increasing intracellular cAMP, causes the following to occur in cardiac Purkinje fibers from sheep: (a) a decrease in intracellular sodium activity when the Na+ pump is functioning normally; (b) a promotion of membrane depolarization in quiescent fibers; (c) an increase in the steepness of the pacemaker potential in electrically stimulated fibers, and (d) an increase in the force of contraction. Therefore, forskolin will be a useful tool for investigating the role of cAMP in physiological function of cardiac cells.
journal_name
J Mol Cell Cardioljournal_title
Journal of molecular and cellular cardiologyauthors
Zalups RK,Sheu SSdoi
10.1016/s0022-2828(87)80617-xsubject
Has Abstractpub_date
1987-09-01 00:00:00pages
887-96issue
9eissn
0022-2828issn
1095-8584pii
S0022-2828(87)80617-Xjournal_volume
19pub_type
杂志文章abstract：:To examine the action of alpha-tocopherol on high energy phosphate compounds, a 31P-NMR technique was applied to perfused Langendorff rat hearts. Rats were treated with tocopherol acetate (25 mg/kg body wt i.p.) for 7 consecutive days. On the 7th day, the rat hearts were isolated for the Langendorff experiment. After ...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1993.1119
更新日期：1993-09-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2004.09.010
更新日期：2004-12-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
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doi：10.1016/0022-2828(92)93153-b
更新日期：1992-02-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2008.12.001
更新日期：2009-03-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1997.0458
更新日期：1997-08-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章,评审
doi：10.1016/j.yjmcc.2011.01.007
更新日期：2011-04-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章,评审
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更新日期：2011-10-01 00:00:00
abstract：:α-Keto acids (α-KAs) are not just metabolic intermediates but are also powerful modulators of different cellular pathways. Here, we tested the hypothesis that α-KA concentrations are regulated by complex II (succinate dehydrogenase=SDH), which represents an intersection between the mitochondrial respiratory chain for ...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2010.09.023
更新日期：2010-12-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2005.08.008
更新日期：2005-12-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2019.03.018
更新日期：2019-05-01 00:00:00
abstract：:MicroRNAs (miRNAs) are small non-coding RNAs that control expression of complementary target mRNAs. A growing number of miRNAs has been implicated in the pathogenesis of cardiac diseases, mostly based not on functional data, but on the observation that they are dysregulated in diseased myocardium. Consequently, our kn...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2011.07.010
更新日期：2012-01-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章,评审
doi：10.1016/j.yjmcc.2009.07.022
更新日期：2010-03-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章,评审
doi：10.1016/s0022-2828(03)00135-4
更新日期：2003-07-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1994.1084
更新日期：1994-06-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1996.0026
更新日期：1996-02-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2005.04.008
更新日期：2005-09-01 00:00:00
abstract：:We have previously proposed that the heterogeneous collapse of mitochondrial inner membrane potential (DeltaPsi(m)) during ischemia and reperfusion contributes to arrhythmogenesis through the formation of metabolic sinks in the myocardium, wherein clusters of myocytes with uncoupled mitochondria and high K(ATP) curren...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2009.11.011
更新日期：2010-04-01 00:00:00
abstract：:In a recent issue of Journal of Molecular and Cellular Cardiology, George et al. [1] identified discoidin domain receptor 2 (DDR2) as a positive modulator of collagen production in cardiac fibroblasts stimulated with angiotensin II (Ang II). DDR2 is a tyrosine kinase collagen receptor and is associated with pathologic...
journal_title：Journal of molecular and cellular cardiology
pub_type： 社论
doi：10.1016/j.yjmcc.2016.01.006
更新日期：2016-02-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2014.08.012
更新日期：2014-11-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1997.0511
更新日期：1997-10-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2011.06.015
更新日期：2011-09-01 00:00:00
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journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2020.07.004
更新日期：2020-09-01 00:00:00
abstract：:The effect of isoproterenol on mechanical function was studied in the isolated arterially perfused heart of the fetal (21st and 28th day of gestation) and newborn rabbits. The inotropic effect of isoproterenol in the fetus was less than in the newborn. In contrast, myocardial cyclic AMP levels after isoproterenol infu...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/s0022-2828(87)80557-6
更新日期：1987-02-01 00:00:00
abstract：:The heart contains many cell types; mechanical work is done by cardiomyocytes which do not divide but are terminally differentiated and capable of continuous protein synthesis and degradation. The steps in protein synthesis are (1) transport of amino acids into heart cells by a variety of cell-membrane carriers, (2) A...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章,评审
doi：10.1016/s0022-2828(84)80711-7
更新日期：1984-01-01 00:00:00
abstract：:The effects of variations in serum concentrations of potassium on the occurrence and severity of ischemia- and reperfusion-induced arrhythmias have been studied in conscious rats. Serum potassium concentrations were modified by maintaining rats on diets which varied in potassium concentration, by treatment with hydroc...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/0022-2828(92)93384-v
更新日期：1992-07-01 00:00:00
abstract：:Hemodynamic and electron spin resonance analyses were used to assess the in vivo and in vitro cardioprotective and antioxidant effects of therapeutically relevant doses of Ginkgo biloba extract (EGb 761) and its terpenoid constituents (ginkgolides A and B, bilobalide) in the rat. Significant anti-ischemic effects, ind...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1996.0316
更新日期：1997-02-01 00:00:00
abstract：:The modulating effects of Ca2+ on single K+ channel currents in canine heart sarcoplasmic reticulum were studied using a planar lipid bilayer technique. The open-state probability and the unitary open-state current both decreased gradually as the Ca2+ concentration was reduced from pCa 3 to pCa 7.5. Each single-channe...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1006/jmcc.1994.1022
更新日期：1994-02-01 00:00:00
abstract：:Despite advances in the treatment of acute tissue ischemia significant challenges remain in effective cytoprotection from ischemic cell death. It has been documented that injected stem cells, such as mesenchymal stem cells (MSCs), can confer protection to ischemic tissue through the release of paracrine factors. The s...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2013.11.010
更新日期：2014-01-01 00:00:00
abstract：:This study examined the hypothesis that the prediabetic metabolic syndrome alters expression, phosphorylation state and binding affinity of cardiac RyR2. Real-time PCR and Western blot analysis were used to assess mRNA and protein expression in the left ventricle, right ventricle and right atrium from control (n=5) an...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2006.04.018
更新日期：2006-07-01 00:00:00
abstract：:Attenuation of excessive rates of myocardial glycolysis limits proton production and Ca(2+) overload during reperfusion and improves recovery of post-ischemic left ventricular (LV) function. In order to elucidate mechanisms underlying glycolytic inhibition by adenosine (ADO), this study tested the hypothesis that the ...
journal_title：Journal of molecular and cellular cardiology
pub_type： 杂志文章
doi：10.1016/j.yjmcc.2012.03.014
更新日期：2012-06-01 00:00:00
