Abstract:
:Coronary pressure-flow relations during autoregulated and vasodilated flow states were compared between eight dogs with renovascular hypertension and left ventricular hypertrophy and 12 normal dogs. Each relation was constructed from serial steady-state measurements of end-diastolic coronary pressure and flow during perfusion of the circumflex artery by an extracorporeal circuit at controlled diastolic pressures of 20-200 mm Hg. Autoregulated pressure-flow relations were compared at three levels of myocardial oxygen demand: resting, high (dobutamine 10 micrograms/kg/min), and low (propranolol 2.5 micrograms/kg/min). Autoregulatory capacity was assessed by calculation of closed-loop flow gain. At each level of myocardial oxygen demand, the lower limit of autoregulation occurred at higher perfusion pressures in the hypertrophy group (rest 65 +/- 3, high 92 +/- 4, low 66 +/- 4 mm Hg) than in the normal group (rest 53 +/- 2, p less than 0.05; high 75 +/- 5, p less than 0.05; low 51 +/- 3 mm Hg) (p less than 0.05). Maximum autoregulatory gain was similar in the normal and hypertrophy groups during resting and low myocardial oxygen demand but was reduced in the hypertrophy group during dobutamine studies. When coronary flow decreased below the lower limit of autoregulation, systolic shortening was reduced in both normal and hypertrophy groups. However, as the autoregulatory limits were at higher pressures in the hypertrophy group, shortening in this group deteriorated at perfusion pressures that did not affect the normal heart. Coronary pressure-flow relations during physiological (peak hyperemia after 15-second flow occlusion) and pharmacologica (intracoronary adenosine 400 micrograms/min) vasodilation was curvilinear and fitted by quadratic regression. During hyperemic vasodilation, maximal conductance per unit mass of myocardium was less in the hypertrophy group over a wide range of perfusion pressures. At a diastolic perfusion pressure of 80 mm Hg, maximum conductance was 4.6 +/- 0.5 ml/min/100 g/mm Hg in the normal group and 3.4 +/- 0.4 ml/min/100 g/mm Hg (p less than 0.05) in the hypertrophy group. Intracoronary adenosine elicited further vasodilation in both groups, but maximum conductance remained less in the hypertrophy group (8.5 +/- 1.7 ml/min/100 g/mm Hg at a perfusion pressure of 80 mm Hg) than in the normal group (13.5 +/- 2.0 ml/min/100 g/mm Hg) (p less than 0.05). Maximal coronary flow reserve is reduced in left ventricular hypertrophy, with a consequent shift of the lower limit of autoregulation to higher perfusion pressures. Thus, as coronary perfusion pressure is decreased, coronary flow and myocardial shortening become impaired at higher
journal_name
Circ Resjournal_title
Circulation researchauthors
Jeremy RW,Fletcher PJ,Thompson Jdoi
10.1161/01.res.65.1.224subject
Has Abstractpub_date
1989-07-01 00:00:00pages
224-36issue
1eissn
0009-7330issn
1524-4571journal_volume
65pub_type
杂志文章abstract::Nitric oxide (NO), generated by platelets through stimulation of nitric oxide synthase (NOS), limits platelet adhesion and aggregation after a prothrombotic stimulus. Platelet beta-adrenoceptors (betaARs) mediate inhibition of aggregation, but no direct link has been shown between these receptors and platelet adhesion...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.87.1.39
更新日期:2000-07-07 00:00:00
abstract::We determined whether local bradykinin production modulates cardiac adrenergic activity. Depolarization of guinea pig heart sympathetic nerve endings (synaptosomes) with 1 to 100 mmol/L K+ caused the release of endogenous norepinephrine (10% to 50% above basal level). This release was exocytotic, because it depended o...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.81.5.774
更新日期:1997-11-01 00:00:00
abstract::Although isoform-selective translocation of protein kinase C (PKC) epsilon appears to play an important role in the late phase of ischemic preconditioning (PC), the mechanism(s) responsible for such translocation remains unclear. Furthermore, the signaling pathway that leads to the development of late PC after exogeno...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.84.5.587
更新日期:1999-03-19 00:00:00
abstract::Twenty-one dogs were studied under conditions of normal oxygenation and hypoxia with the microsphere distribution method to determine the effect of arterial oxygen saturation on the regional distribution of cardiac output. The dogs were anesthetized and artifically ventilated. Cannulas were placed in the left ventricl...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.39.3.314
更新日期:1976-09-01 00:00:00
abstract:RATIONALE:Smooth muscle precursor cells have previously been reported to reside in bone marrow and in the circulation, but little is currently known regarding the proximate stimuli for smooth muscle cell differentiation of these putative progenitors. OBJECTIVE:Because local thrombin generation occurs as an initial res...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.109.199984
更新日期:2009-07-31 00:00:00
abstract::Accumulation of plasminogen activator inhibitor type 1 (PAI-1) in the arterial wall may accelerate atherogenesis by inhibiting fibrinolysis, diminishing proteolysis of extracellular matrix proteins, or modifying migration of vascular smooth muscle cells. Increased intramural expression of the PAI-1 gene is induced by ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.73.4.671
更新日期:1993-10-01 00:00:00
abstract:RATIONALE:MicroRNAs (miRNAs) are short noncoding RNA species generated by the processing of longer precursors by the ribonucleases Drosha and Dicer. Platelets contain large amounts of miRNA that are altered by disease, in particular diabetes mellitus. OBJECTIVE:This study determined why platelet miRNA levels are atten...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.117.305784
更新日期:2015-07-03 00:00:00
abstract::The deposition of platelets at the site of balloon angioplasty is thought to play a major role in the pathogenesis of restenosis. The antibody AZ-1, which binds to the rabbit platelet glycoprotein IIb/IIIa receptor and inhibits platelet function both in vitro and in vivo, was produced and tested in an experimental mod...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.75.2.268
更新日期:1994-08-01 00:00:00
abstract:RATIONALE:Mitochondrial dysfunction plays an important role in heart failure (HF). However, the molecular mechanisms regulating mitochondrial functions via selective mitochondrial autophagy (mitophagy) are poorly understood. OBJECTIVE:We sought to determine the role of AMPK (AMP-activated protein kinase) in selective ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.117.312317
更新日期:2018-03-02 00:00:00
abstract::The global prevalence of overweight and obesity has risen substantially over the past 4 decades and is accompanied by an increasing burden of cardiovascular risk factors such as hypertension. Metabolic surgery is the most effective method to treat obesity and may further improve associated conditions. Although most re...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.118.313320
更新日期:2019-03-29 00:00:00
abstract:RATIONALE:ATP-binding cassette transporter A1 (ABCA1) plays a critical role in eliminating excess free cholesterol from tissues by effluxing cellular free cholesterol and phospholipids to lipid-poor apolipoprotein AI. Macrophage ABCA1 also dampens proinflammatory myeloid differentiation primary-response protein 88-depe...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.112.269043
更新日期:2012-11-09 00:00:00
abstract:RATIONALE:One goal of cardiac tissue engineering is the generation of a living, human pump in vitro that could replace animal models and eventually serve as an in vivo therapeutic. Models that replicate the geometrically complex structure of the heart, harboring chambers and large vessels with soft biomaterials, can be...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.119.316155
更新日期:2020-07-03 00:00:00
abstract::Patients with peripheral artery disease (PAD) are at heightened risk of both systemic cardiovascular adverse events, as well as limb-related morbidity. The optimal management of patients with PAD requires a comprehensive treatment strategy incorporating both lifestyle changes, including smoking cessation and exercise,...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.114.303505
更新日期:2015-04-24 00:00:00
abstract::Volume expansion has been shown to increase plasma atrial natriuretic peptide (ANP) levels, but the precise role of paracrine and autocrine factors in stretch-induced cardiac hormone release is not clear. In the present study, we report the effects of endothelin (ET) and angiotensin receptor (AT receptor) antagonists ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.80.1.114
更新日期:1997-01-01 00:00:00
abstract::We studied the mechanisms underlying the increase in automaticity induced by alpha 1-adrenergic stimulation of normal and "ischemic" canine Purkinje fibers. Fibers were superfused with a control Tyrode's solution, followed by an ischemic superfusate that included 10 mM KCl, 5 mM NaHCO3, Po2 of 10-25 mm Hg, and pH 6.7....
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.71.3.526
更新日期:1992-09-01 00:00:00
abstract:RATIONALE:We have previously demonstrated that the importance of endothelium-derived hyperpolarizing factor (EDHF) increases as the vessel size decreases and that endothelium-derived hydrogen peroxide (H(2)O(2)) is an EDHF in animals and humans, for which endothelial nitric oxide synthase (eNOS) is the major source. Re...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.112.270215
更新日期:2012-06-22 00:00:00
abstract::This article examines the role of innervation in regulating expression of acetylcholinesterase (AchE), butyrylcholinesterase (BuchE), and the muscarinic acetylcholine receptor (mAchR) in avian heart. Two distinct approaches are taken. The first approach examines the relation between the onsets of parasympathetic and s...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.70.4.633
更新日期:1992-04-01 00:00:00
abstract::Electrical uncoupling at gap junctions during acute myocardial ischemia contributes to conduction abnormalities and reentrant arrhythmias. Increased levels of intracellular Ca(2+) and H(+) and accumulation of amphipathic lipid metabolites during ischemia promote uncoupling, but other mechanisms may play a role. We tes...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.87.8.656
更新日期:2000-10-13 00:00:00
abstract::Alpha1-adrenoceptor (alpha1-AR) stimulation increases sarcolemmal Na+-H+ exchanger (NHE) activity. The present study was designed to determine the role(s) of alpha1-AR subtype(s) in mediating this response. As an index of NHE activity, acid efflux rates (JHs) were determined in single rat ventricular myocytes loaded w...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.82.10.1078
更新日期:1998-06-01 00:00:00
abstract::Understanding the molecular interactions among components of cardiac Z-discs and their role in signaling has become pivotal in explaining long- and short-term regulation of cardiac function. In striated muscle, the ends of the thin filaments from opposing sarcomeres overlap and are cross-linked by an elaborate array o...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/01.RES.0000116143.74830.A9
更新日期:2004-02-20 00:00:00
abstract::We have used an immunological approach to investigate the role of myosin light chain phosphorylation (MLC-Pi) in the control of contractility in smooth muscle. Our aim was to specifically inhibit myosin light chain kinase (MLCK) in the presence of physiologically activating levels of Ca2+ so that other putative Ca2(+)...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.68.2.457
更新日期:1991-02-01 00:00:00
abstract:RATIONALE:Shear stress (SS) has an established role in atherosclerotic plaque localization, but how it exerts its protective effect is not fully understood. OBJECTIVE:To test the hypothesis that SS may downregulate angiotensin type 1 receptors (AT(1)Rs). Angiotensin II has been shown to be proinflammatory and to promo...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.109.204040
更新日期:2009-10-23 00:00:00
abstract::Vascular smooth muscle cell (VSMC) proliferation is a critical event in the development and progression of vascular diseases, including atherosclerosis. We investigated whether the activation of adenosine monophosphate-activated protein kinase (AMPK) could suppress VSMC proliferation and inhibit cell cycle progression...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000185823.73556.06
更新日期:2005-10-14 00:00:00
abstract:RATIONALE:Clinical benefits of reperfusion after myocardial infarction are offset by maladaptive innate immune cell function, and therapeutic interventions are lacking. OBJECTIVE:We sought to test the significance of phagocytic clearance by resident and recruited phagocytes after myocardial ischemia reperfusion. METH...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.117.311327
更新日期:2017-09-29 00:00:00
abstract::Heart failure is associated with death of cardiomyocytes leading to loss of contractility. Previous studies using membrane-targeted Akt (myristolated-Akt), an enzyme involved in antiapoptotic signaling, showed inhibition of cell death and prevention of pathogenesis induced by cardiomyopathic stimuli. However, recent s...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000124394.01180.BE
更新日期:2004-04-16 00:00:00
abstract::Endothelial cells release nitric oxide (NO) more potently in response to increased shear stress than to agonists which elevate intracellular free calcium concentration ([Ca2+]i). To determine mechanistic differences in the regulation of endothelial constitutive NO synthase (ecNOS), we measured NO production by bovine ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.79.5.984
更新日期:1996-11-01 00:00:00
abstract::When exposed to an increasing transmural pressure, middle cerebral arteries of the cat exhibit reduction of internal diameter which is mediated by vascular muscle cell depolarization. This laboratory has recently demonstrated that this "pressure-induced" activation is dependent upon the presence of an intact endotheli...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.65.1.193
更新日期:1989-07-01 00:00:00
abstract::Peripheral vasodilator responsiveness was examined in pacing-induced heart failure (HF) in 11 conscious dogs chronically instrumented for measurement of systemic (total peripheral resistance [TPR]) and local (iliac blood flow) vascular resistance. Dose responses to isoproterenol (ISO), acetylcholine (ACh), and nitrogl...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.73.6.1013
更新日期:1993-12-01 00:00:00
abstract::Radiolabeled triiodothyronine (T3) binding to isolated nuclei was measured to compare the binding characteristics of the nuclear receptors in rabbit ventricular and atrial muscle cells. Scatchard analysis of the binding data yielded a maximum binding capacity of 170 +/- 20 fmol per mg DNA and apparent dissociation con...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.63.1.267
更新日期:1988-07-01 00:00:00
abstract::Three models of altered autonomic innervation of the chick heart have been developed in the last few years. These include sympathetically aneural heart, parasympathetically aneural heart, and heart with cholinergic innervation reconstituted from the nodose placodes. The neural status of these hearts has been assessed ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.65.6.1547
更新日期:1989-12-01 00:00:00