Abstract:
:To gain some insight into inotropic mechanisms, we compared the effects of several classes of inotropic interventions on the isometric twitch and force-velocity properties of isolated rabbit myocardium. Postextrasystolic potentiation was chosen as one of the interventions in the belief that its onset is so rapid that it would be unlikely to cause substantial chemical changes in the contractile proteins and that most of the effects would be due to changes in the level of activation. The effects of a digitalis analogue (acetylstrophanthidin), an adrenergic agent (isoproterenol), and a methylxanthine (caffeine) were then compared with those of postextrasystolic potentiation. The conditions were chosen so that each agent caused a twofold increase in twitch force. Acetylstrophanthidin and postextrasystolic potentiation caused twitch force to increase with only a slight (11%) decrease in time to peak force. Isoproterenol caused the peak of the twitch to occur substantially (40%) earlier with marked abbreviation of the twitch. Caffeine had the opposite effect: time to peak force was delayed (by 60%), and the twitch was markedly prolonged. In contrast to the marked differences in the time course of the twitch, there was no significant difference between the instantaneous force-velocity curves obtained with the different interventions. All four interventions caused maximum velocity to increase slightly (1-9%) and maximum power to increase only slightly more than twitch force (5-21%). All of the changes observed can be accounted for by changes in activation, either by an increase in the amount of calcium released into the myofilament space or by a change in the sensitivity of the myofilaments to calcium. There was no need to postulate direct changes in the contractile machinery to account for these results.
journal_name
Circ Resjournal_title
Circulation researchauthors
Chiu YC,Walley KR,Ford LEdoi
10.1161/01.res.65.5.1161subject
Has Abstractpub_date
1989-11-01 00:00:00pages
1161-71issue
5eissn
0009-7330issn
1524-4571journal_volume
65pub_type
杂志文章abstract::We have recently characterized the promoter region of the rabbit embryonic smooth muscle myosin heavy chain (SMemb/NMHC-B) gene and identified the 15-bp sequence, designated SE1, located at -105 from the transcriptional start site as an important regulatory element for its transcriptional activity in a smooth muscle c...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.85.2.182
更新日期:1999-07-23 00:00:00
abstract:RATIONALE:Gq signaling in cardiac myocytes is classically considered toxic. Targeting Gq directly to test this is problematic, because cardiac myocytes have many Gq-coupled receptors. OBJECTIVE:Test whether Gq coupling is required for the cardioprotective effects of an alpha-1A-AR (adrenergic receptor) agonist. METHO...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.118.314416
更新日期:2019-09-13 00:00:00
abstract:RATIONALE:Wnt signaling regulates key aspects of diabetic vascular disease. OBJECTIVE:We generated SM22-Cre;LRP6(fl/fl);LDLR(-/-) mice to determine contributions of Wnt coreceptor low-density lipoprotein receptor-related protein 6 (LRP6) in the vascular smooth muscle lineage of male low-density lipoprotein receptor-nu...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.117.306712
更新日期:2015-07-03 00:00:00
abstract::A distal transcriptional enhancer has been previously reported upstream of the mouse renin gene. A homologous sequence is also present upstream of the human renin gene, but the mouse and human renin enhancers differ markedly in their ability to activate transcription of a renin promoter. Although the 2 enhancers share...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.85.6.479
更新日期:1999-09-17 00:00:00
abstract::To determine the time course of efferent sympathetic denervation after transmural myocardial infarction (TMI) and of efferent vagal denervation after transmural or nontransmural myocardial infarction (NTMI), we measured effective refractory periods (ERP) basal and apical to TMI or NTMI in secobarbital-anesthetized, op...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.62.6.1111
更新日期:1988-06-01 00:00:00
abstract::Hypertrophic (HCM) and dilated (DCM) cardiomyopathies are inherited diseases with a high incidence of death due to electric abnormalities or outflow tract obstruction. In many of the families afflicted with either disease, causative mutations have been identified in various sarcomeric proteins. In this review, we focu...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.110.223842
更新日期:2012-07-20 00:00:00
abstract::Previous studies have demonstrated that cGMP and cAMP reduce the endothelial permeability for fluids and macromolecules when the endothelial permeability is increased by thrombin. In this study, we have investigated the mechanism by which cGMP improves the endothelial barrier function and examined whether nitric oxide...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.76.2.199
更新日期:1995-02-01 00:00:00
abstract::The realization of regenerative cardiac medicine depends on the availability of cardiomyocytes in sufficient numbers for transplantation of cardiac tissue and the accompanying blood vessels. Embryonic stem (ES) cells, bone marrow (BM) stem cells, and tissue-derived stem cells are all potential cell sources. Although E...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/01.RES.0000218272.18669.6e
更新日期:2006-04-28 00:00:00
abstract::Direct binding of apolipoprotein (apo)B-containing lipoproteins to proteoglycans is the initiating event in atherosclerosis, but the processes involved at later stages of development are unclear. Here, we investigated the importance of the apoB-proteoglycan interaction in the development of atherosclerosis over time a...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.107.149666
更新日期:2007-10-12 00:00:00
abstract::Proliferation of vascular smooth muscle cells (VSMC) is a primary cause of vascular disorders and is associated with major alterations in Ca2+ handling supported by loss of the sarco/endoplasmic reticulum calcium ATPase, SERCA2a. To determine the importance of SERCA2a in neointima formation, we have prevented loss of ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000180663.42594.aa
更新日期:2005-09-02 00:00:00
abstract:RATIONALE:Circumstantial evidence links the development of heart failure to posttranslational modifications of mitochondrial proteins, including lysine acetylation (Kac). Nonetheless, direct evidence that Kac compromises mitochondrial performance remains sparse. OBJECTIVE:This study sought to explore the premise that ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.120.317293
更新日期:2020-09-25 00:00:00
abstract::Selective troponin I (TnI) modification has been demonstrated to be in part responsible for the contractile dysfunction observed with myocardial ischemia/reperfusion injury. We have isolated and characterized modified TnI products in isolated rat hearts after 0, 15, or 60 minutes of ischemia followed by 45 minutes of ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.84.1.9
更新日期:1999-01-08 00:00:00
abstract::The mechanism(s) by which mutations in sarcomeric proteins cause hypertrophic cardiomyopathy (HCM) remains unknown. A leading hypothesis proposes that mutant sarcomeric proteins impair cardiac myocyte contractility, providing an impetus for compensatory hypertrophy. To test this hypothesis, we determined the impact of...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.81.1.76
更新日期:1997-07-01 00:00:00
abstract::In this study, anti-basic fibroblast growth factor (anti-bFGF) antibody was used to determine whether the mitogenic effect of angiotensin II in vivo could be blocked by neutralizing bFGF in the vessel wall. Animals, divided into six experimental groups, were given (1) angiotensin II, (2) angiotensin II + anti-bFGF ant...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/01.res.82.3.321
更新日期:1998-02-23 00:00:00
abstract::An improved assay was used to investigate the effects of hypoxia or ischemia on interstitial fluid and coronary venous effluent levels of adenosine in isolated perfused nonworking rat hearts. The adenosine in 5- to 10-microliter samples of left ventricular epicardial surface transudates and coronary effluents was reac...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.60.2.177
更新日期:1987-02-01 00:00:00
abstract::Na(v)1.5, the cardiac isoform of the voltage-gated Na+ channel, is critical to heart excitability and conduction. However, the mechanisms regulating its expression at the cell membrane are poorly understood. The Na(v)1.5 C-terminus contains a PY-motif (xPPxY) that is known to act as binding site for Nedd4/Nedd4-like u...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000136816.05109.89
更新日期:2004-08-06 00:00:00
abstract:RATIONALE:We previously reported that vascular endothelial growth factor (VEGF)-induced binding of VEGF receptor 2 (VEGFR2) to epsins 1 and 2 triggers VEGFR2 degradation and attenuates VEGF signaling. The epsin ubiquitin interacting motif (UIM) was shown to be required for the interaction with VEGFR2. However, the mole...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.115.307679
更新日期:2016-03-18 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::The present study was designed to test the ability of regenerated endothelium to evoke endothelium-dependent hyperpolarizations. Hyperpolarizations induced by serotonin and bradykinin were compared in isolated porcine coronary arteries with native or regenerated endothelium, 4 weeks after balloon endothelial denudatio...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.84.4.371
更新日期:1999-03-05 00:00:00
abstract::Membrane current abnormalities have been described in human heart failure. To determine whether similar current changes are observed in a large animal model of heart failure, we studied dogs with pacing-induced cardiomyopathy. Myocytes isolated from the midmyocardium of 13 dogs with heart failure induced by 3 to 4 wee...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.78.2.262
更新日期:1996-02-01 00:00:00
abstract::5-Hydroxytryptamine (5-HT)(1B) receptors mediate contraction in human pulmonary arteries, and 5-HT(1B) receptor-mediated contraction is enhanced in pulmonary arteries from hypoxic rats. Here we further examine the role of this receptor in the development of pulmonary hypertension (PHT) by examining (1) the effects of ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/hh2401.100426
更新日期:2001-12-07 00:00:00
abstract::Sympathetic activation appears to accelerate the development of atherosclerosis, an effect that may be inhibited by beta-receptor blockade. It is unclear, however, which mechanisms mediate this effect. In view of the significance attached to endothelial injury in the initial phases of atherogenesis, we decided to test...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.67.4.1027
更新日期:1990-10-01 00:00:00
abstract::Transcriptional thyroid hormone responsiveness of the cardiac alpha-myosin heavy chain (alpha-MHC) gene has been demonstrated in transfections into fetal and neonatal cardiomyocytes and in transgenic mice. However, the correspondence between the regulation of MHC expression in dissociated cells with that in the intact...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.72.6.1211
更新日期:1993-06-01 00:00:00
abstract::An extensive investigation of the cardiac actions of phorbol esters and the potential role of the Na(+)-H+ exchanger in those actions was carried out using isolated rat hearts. Sixty minutes of perfusion with 10(-9) M phorbol 12-myristate 13-acetate (PMA) or 10(-8) M phorbol 12,13-dibutyrate (PDBu) produced marked car...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.69.4.1114
更新日期:1991-10-01 00:00:00
abstract::Increasing attention is currently devoted to the multiple roles that pericytes (also defined as mural, Rouget, or perivascular cells) may play during angiogenesis, vascular homeostasis, and pathology. Many recent excellent reviews thoroughly address these topics (see below); hence, we will not discuss them in detail h...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.113.300203
更新日期:2013-07-19 00:00:00
abstract::The microelectrode technique of intracellular constant current application and intracellular transmembrane voltage recording was used to study the effects of procaine amide (PA) on cardiac excitability. We measured the effect of PA in a concentration equivalent to clinically effective antiarrhythmic plasma levels (5 m...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.38.2.115
更新日期:1976-02-01 00:00:00
abstract::Heme oxygenase (HO) is a cytoprotective enzyme that degrades heme (a potent oxidant) to generate carbon monoxide (a vasodilatory gas that has anti-inflammatory properties), bilirubin (an antioxidant derived from biliverdin), and iron (sequestered by ferritin). Because of properties of HO and its products, we hypothesi...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/hh1001.091521
更新日期:2001-05-25 00:00:00
abstract::The action potential model presented in our accompanying article in this journal is used to investigate phenomena that involve dynamic changes of [Ca2+]i, as described below. Delayed afterdepolarizations (DADs) are induced by spontaneous Ca2+ release from the sarcoplasmic reticulum (SR), which, in turn, activates both...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.74.6.1097
更新日期:1994-06-01 00:00:00
abstract::The mitochondrial enzyme monoamine oxidase (MAO), its isoform MAO-A, plays a major role in reactive oxygen species-dependent cardiomyocyte apoptosis and postischemic cardiac damage. In the current study, we investigated whether sphingolipid metabolism can account for mediating MAO-A- and reactive oxygen species-depend...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000253900.66640.34
更新日期:2007-01-05 00:00:00
abstract:RATIONALE:The vascular adventitia is a complex layer of the vessel wall consisting of vasa vasorum microvessels, nerves, fibroblasts, immune cells, and resident progenitor cells. Adventitial progenitors express the stem cell markers, Sca1 and CD34 (adventitial sca1-positive progenitor cells [AdvSca1]), have the potenti...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.116.309322
更新日期:2017-01-20 00:00:00