Abstract:
:The effects of sodium pump inhibition produced by exposure to the cardiac glycosides, ouabain or dihydroouabain, or by reduction in extracellular potassium to 1.0 mM, on contractile state and sodium-calcium exchange were studied in primary monolayer cultures of chick embryo ventricular cells. Ouabain, 10(-6)M, dihydroouabain, 5 X 10(-5)M, and extracellular potassium of 1.0 mM all induced similar and prominent positive inotropic effects. These effects were accompanied, in each case, by 40-50% inhibition of the rate of active uptake of 42K and by similar increases in steady state sodium content. Stimulation of the rate of 45Ca uptake on exposure to zero extracellular sodium occurred in response to extracellular potassium (1.0 mM) or to glycoside concentrations that induced a positive inotropic effect and sodium-potassium pump inhibition. Reactivation of the sodium pump after return from 1.0 to 4.0 mM extracellular potassium was rapid and was associated with membrane hyperpolarization and slowing of spontaneous beating rate. With pump reactivation under these circumstances, the time course of disappearance of stimulation of sodium-calcium exchange on exposure to zero extracellular sodium was similar to the time course of loss of the positive inotropic effect. Under physiological conditions (4.0 mM extracellular potassium), exposure to positively inotropic but nontoxic concentrations of ouabain or dihydroouabain caused a small but consistent increase in unidirectional calcium influx, but had no discernible effect on calcium efflux. Since similar inotropic effects were produced for comparable degrees of glycoside or low extracellular potassium-induced sodium pump inhibition and increases in cellular sodium content, sodium pump inhibition rather than a glycoside-specific change in calcium binding appears to underlie the inotropic response. These findings are further consistent with the view that the primary mechanism of the positive inotropic effects of digitalis and low extracellular potassium in this experimental preparation is sodium pump inhibition resulting in increased intracellular sodium. We suggest that increased calcium influx via sodium-calcium exchange is the principal mechanism whereby increased intracellular sodium results in enhanced calcium availability to the myofibrils, but an additional effect on calcium efflux is not excluded.
journal_name
Circ Resjournal_title
Circulation researchauthors
Barry WH,Hasin Y,Smith TWdoi
10.1161/01.res.56.2.231subject
Has Abstractpub_date
1985-02-01 00:00:00pages
231-41issue
2eissn
0009-7330issn
1524-4571journal_volume
56pub_type
杂志文章abstract:RATIONALE:The embryonic epicardium is a crucial cell source of the cardiac fibrous skeleton as well as of the coronary system. Genetic lineage tracing systems based on Wt1 regulatory sequences provided evidence that epicardium-derived cells also adopt a myocardial fate in the mouse. OBJECTIVE:To define the adequacy of...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.112.273946
更新日期:2012-07-06 00:00:00
abstract::Although urinary sodium excretion is positively influenced by acute changes in renal perfusion pressure, micropuncture studies show highly conflicting results concerning the response of superficial proximal tubule sodium reabsorption to changes in renal perfusion pressure. In the present study, the changes of superfic...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.66.5.1184
更新日期:1990-05-01 00:00:00
abstract::Physiological or pathological stresses and strains produce longer or wider muscle cells, but resting sarcomere length remains constant. Our goal was to investigate the cellular mechanisms for controlling this optimal, resting sarcomere length. To do so, we cultured neonatal rat cardiomyocytes on microfabricated peg-an...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000121101.32286.C8
更新日期:2004-03-19 00:00:00
abstract::The potential for exogenous infusion of basic fibroblast growth factor (bFGF) to increase collateral blood flow to dependent tissue was quantified in adult male rats with peripheral arterial insufficiency. Occlusion of the femoral artery at a proximal site did not infringe on resting blood flow to the distal hindlimb ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.79.1.62
更新日期:1996-07-01 00:00:00
abstract::Electrocardiogram (ECG) electrodes and carotid arterial and superior vena caval (SVC) catheters were placed in eight nonpregnant ewes and 11 fetuses (109-129 days gestation) to measure heart rate, arterial presssure, P-R interval, left ventricular pre-ejection period (PEP), and left ventricular ejection time (LVET), b...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.41.5.635
更新日期:1977-11-01 00:00:00
abstract::Complete knowledge of myocardial structure, metabolism, and function is crucial to understanding the response of the heart to injury such as ischemia. Increasingly, this type of knowledge is required at multiple levels, from that of the isolated myocyte to the functioning organism, to provide basic scientists and clin...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/01.RES.0000103863.40055.E8
更新日期:2003-12-12 00:00:00
abstract::Activity was recorded from physiologically identified baroreceptor or chemoreceptor fibers in carotid sinus nerves of urethane-anesthetized spontaneously breathing rabbits. A carotid sinus area was vascularly isolated so that carotid sinus pressure and perfusion medium (Locke's solution or rabbit blood) could be contr...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.69.6.1608
更新日期:1991-12-01 00:00:00
abstract::Triadin 1 (TRD) is an integral membrane protein that associates with the ryanodine receptor (RyR2), calsequestrin (CASQ2) and junctin to form a macromolecular Ca signaling complex in the cardiac junctional sarcoplasmic reticulum (SR). To define the functional role of TRD, we examined the effects of adenoviral-mediated...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000160609.98948.25
更新日期:2005-04-01 00:00:00
abstract:RATIONALE:autophagy, a bulk degradation process of cytosolic proteins and organelles, is protective during nutrient starvation in cardiomyocytes (CMs). However, the underlying signaling mechanism mediating autophagy is not well understood. OBJECTIVE:we investigated the role of FoxOs and its posttranslational modificat...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.110.227371
更新日期:2010-12-10 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.77.3.475
更新日期:1995-09-01 00:00:00
abstract::Hypercholesterolemia induces atheroma formation, and the concentration of sphingomyelin is increased compared with that in the normal aortic intima-media. The aortic intima-media sphingomyelin concentration appears to increase exponentially with time on the cholesterol diet. Moreover, the entry rate of serum sphingomy...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.36.2.294
更新日期:1975-02-01 00:00:00
abstract::The purpose of this study was to investigate the nature of the serotonin-induced coronary chemoreflex in the conscious monkey. Ten chronically prepared and four acute monkeys were used in this study. Five chronically prepared animals had catheters in the left atrium, ascending aorta, descending aorta, and, bilaterally...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.52.3.312
更新日期:1983-03-01 00:00:00
abstract::Regional myocardial oxygenation was assessed during partial and complete coronary artery occlusion using near infrared spectroscopy. In eight open-chest dogs, partial occlusions resulting in an approximately 42% decrease in left anterior descending coronary artery (LAD) blood flow produced an approximately 21% decreas...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.73.3.458
更新日期:1993-09-01 00:00:00
abstract::Controversy exists regarding the mechanism by which catecholamines stimulate renin secretion in vivo. A sensitive rat kidney slice system was utilized to study the direct effects of adrenergic agonists and antagonists on renin release in vitro. Catecholamines were protected from degradation by the addition of ascorbic...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.37.3.318
更新日期:1975-09-01 00:00:00
abstract::Cyclic nucleotides are known to modify voltage-gated (L-type) Ca2+ channel activity in vascular smooth muscle cells, but the exact mechanism(s) underlying these effects is not well defined. The purpose of the present study was to investigate the modulatory role of the cAMP- and cGMP-dependent protein kinase (PKA and P...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.82.5.557
更新日期:1998-03-23 00:00:00
abstract::Heme oxygenase (HO)-1 is a protective antioxidant enzyme that prevents cardiomyocyte apoptosis, for instance, during progressive cardiomyopathy. Here we identify a fundamental aspect of the HO-1 protection mechanism by demonstrating that HO-1 activity in mouse heart stimulates the bigenomic mitochondrial biogenesis pr...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000338597.71702.ad
更新日期:2008-11-21 00:00:00
abstract::Increased levels of C-peptide, a cleavage product of proinsulin, circulate in patients with insulin resistance and early type 2 diabetes mellitus. Recent data suggest a potential causal role of C-peptide in atherogenesis by promoting monocyte and T-lymphocyte recruitment into the vessel wall. The present study examine...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000251231.16993.88
更新日期:2006-11-24 00:00:00
abstract::Cardiomyocyte hypertrophy is transcriptionally controlled and inhibited by glycogen synthase kinase 3beta (GSK3beta). Myocardin is a muscle-specific transcription factor with yet unknown relation to hypertrophy. Therefore, we investigated whether myocardin is sufficient to induce cardiomyocyte hypertrophy and whether ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000184684.88750.FE
更新日期:2005-09-30 00:00:00
abstract::The regeneration of new myocardium by stem or progenitor cells is an important therapeutic option. Cellular or nuclear fusion is considered as an alternative to cell reprogramming by transdifferentiation. However, the generation of hybrid cells may also be a consequence of a transient transmembrane exchange of protein...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000168650.23479.0c
更新日期:2005-05-27 00:00:00
abstract::The synthesis of an angiotensin II (A II) antagonist, sarcosyl1-cysteinyl(S-methyl)8-angiotensin II [Sar1-Cys(Me)8-A II], showing partial organ selectivity and properties of a noncompetitive antagonist, is described. The compound was found to be an extremely potent antagonist on vascular smooth muscle both in vitro (p...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.46.5.720
更新日期:1980-05-01 00:00:00
abstract::To determine whether nifedipine, a calcium antagonist, protects ischemic myocardium, conscious dogs were subjected to coronary occlusion and given nifedipine by intravenous infusion beginning 30 minutes after the onset of ischemia and lasting for 24 hours while systemic arterial pressure, left atrial pressure, and car...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.43.3.372
更新日期:1978-09-01 00:00:00
abstract::The patch-clamp technique was used to examine the inhibition of delayed rectifier K+ channels by agents that release intracellular Ca2+. During voltage-clamp experiments on isolated myocytes with 4-aminopyridine (4-AP, 10 mmol/L) and niflumic acid (100 mumol/L) present to inhibit delayed rectifier K+ current (IK(dr)) ...
journal_title:Circulation research
pub_type: 杂志文章,收录出版
doi:10.1161/01.res.77.1.121
更新日期:1995-07-01 00:00:00
abstract::We have recently shown that adult canine ventricular myocytes express three distinct gap junction channel proteins, connexin40 (Cx40), connexin43 (Cx43), and connexin45 (Cx45). These proteins have unique cytoplasmic domains that likely confer connexin-specific physiological properties. To determine whether the three d...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.73.2.344
更新日期:1993-08-01 00:00:00
abstract::Alveolar epithelial beta-adrenergic receptor (betaAR) activation accelerates active Na+ transport in lung epithelial cells in vitro and speeds alveolar edema resolution in human lung tissue and normal and injured animal lungs. Whether these receptors are essential for alveolar fluid clearance (AFC) or if other mechani...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000125623.56442.20
更新日期:2004-04-30 00:00:00
abstract::Atrial fibrillation (AF) may result from stationary reentry in the left atrium (LA), with fibrillatory conduction toward the right atrium (RA). We hypothesize that periodic input to the RA at an exceedingly high frequency results in disorganized wave propagation, compatible with fibrillatory conduction. Simultaneous e...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.0000022854.95998.5c
更新日期:2002-06-14 00:00:00
abstract::The small (21 kDa) guanine nucleotide-binding protein (small G protein) superfamily comprises 5 subfamilies (Ras, Rho, ADP ribosylation factors [ARFs], Rab, and Ran) that act as molecular switches to regulate numerous cellular responses. Cardiac myocyte hypertrophy is associated with cell growth and changes in the cyt...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/01.res.86.10.1019
更新日期:2000-05-26 00:00:00
abstract::Hibernating myocardium, characterized by reductions in flow and function at rest, has limited contractile reserve in response to increases in external workload. We hypothesized that this attenuation of function reflects an adaptive downregulation that prevents the development of metabolic evidence of ischemia during s...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.0000049104.57549.03
更新日期:2003-01-10 00:00:00
abstract::To investigate the possible contributions of cardiac volume overload and cardiac sympathetic hyperactivity in the effects of sodium on cardiac mass, we evaluated the effects of treatment with saline (1%) and deoxycorticosterone acetate + saline (DOCA/saline) for 10 days and 3 and 6 weeks on ventricular anatomy and int...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.68.3.745
更新日期:1991-03-01 00:00:00
abstract:RATIONALE:Senescence of pulmonary artery smooth muscle cells (PA-SMCs) caused by telomere shortening or oxidative stress may contribute to pulmonary hypertension associated with chronic lung diseases. OBJECTIVE:To investigate whether cell senescence contributes to pulmonary vessel remodeling and pulmonary hypertension...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.111.241299
更新日期:2011-08-19 00:00:00
abstract::We investigated expression of the 5'-spliced isoform of smooth muscle myosin heavy chain (SM-MHC-B) in smooth muscle cells of cardiac vessels of the left ventricle of normotensive (Wistar-Kyoto) and spontaneously hypertensive rats of the stroke-prone strain by immunofluorescence microscopy. In parallel, liver and blad...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.83.2.204
更新日期:1998-07-27 00:00:00