Abstract:
:True propagation coefficients of pulse wave harmonics in an artery can be determined in vivo by measuring pulsatile blood pressure and flow at each of two points along the length of the vessel. These coefficients, which are complex numbers that describe the attenuation and the phase shift imposed on a traveling wave, are independent of the reflected waves in the circulation and thus provide information about the viscoelastic state and other properties of an artery. The equations involved are implicit in standard transmission-line theory, but they have not previously been applied in this particular way to blood vessels. The femoral artery, exposed in situ, was studied in 11 anesthetized dogs. At 1.5 Hz, true attenuation constants averaged 0.0151 nepers/cm, and true phase constants averaged 0.0155 radians/cm. As frequency increased, the apparent phase velocity of flow, in contrast, was relatively low at the first harmonic and rose as frequency increased. True phase velocities lay between the apparent pressure and flow values. Characteristic impedance at 1.5 Hz had an average modulus of 1.76 times 10-4 dyne sec/cm5 and a phase of minus 0.31 radians. The modulus diminished as frequency increased, and the phase became less negative. These results show that true phase constants and characteristic impedances determined by this method are consistent with data reported by others and provide information not previously available about flow wave propagation.
journal_name
Circ Resjournal_title
Circulation researchauthors
Milnor WR,Nichols WWdoi
10.1161/01.res.36.5.631subject
Has Abstractpub_date
1975-05-01 00:00:00pages
631-9issue
5eissn
0009-7330issn
1524-4571journal_volume
36pub_type
杂志文章abstract::Topical application of sodium arachidonate (50-200 micrograms/ml) or bradykinin (0.1-10 micrograms/ml) on the brain surface of anesthetized cats caused dose-dependent cerebral arteriolar dilation. This dilation was blocked by 67-100% in the presence of superoxide dismutase and catalase. These enzymes did not affect th...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.55.3.295
更新日期:1984-09-01 00:00:00
abstract::In this review current hypotheses for the regulation of filtration rate and the subsequent reabsorption of that filtrate by the proximal tubule are discussed. In the rat the filtration rate is highly plasma flow dependent because of the phenomenon of filtration equilibrium. On the other hand, in man and dog filtration...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/01.res.36.6.107
更新日期:1975-06-01 00:00:00
abstract::Changes in cardiac filling pressure (central venous pressure) were measured following carotid occlusion and infusions of catecholamines in awake dogs while cardiac output was held constant. After carotid occlusion in dogs with vagi blocked, central venous pressure increased about 0.8 mm Hg (an estimated decrease in va...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.55.4.440
更新日期:1984-10-01 00:00:00
abstract::Large-conductance Ca2+-dependent K+ channels (KCa), which are abundant on the sarcolemma of vascular myocytes, provide negative feedback via membrane hyperpolarization that limits Ca2+ entry through L-type Ca2+ channels (ICaL). We hypothesize that local accumulation of subsarcolemmal Ca2+ during ICaL openings amplifie...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.84.9.1032
更新日期:1999-05-14 00:00:00
abstract::Adipose tissue (AT) plays a central role in both metabolic health and pathophysiology. Its expansion in obesity results in increased mortality and morbidity, with contributions to cardiovascular disease, diabetes mellitus, fatty liver disease, and cancer. Obesity prevalence is at an all-time high and is projected to b...
journal_title:Circulation research
pub_type: 评审
doi:10.1161/CIRCRESAHA.120.316203
更新日期:2020-05-22 00:00:00
abstract::The impact of vanadate on the Na,K-ATPase system in the vascular smooth muscle cell is poorly understood. The present study describes the kinetics of the effect of vanadate on Na,K-ATPase and the Na-K pump in in vitro grown rat VSMC's. Vanadate interaction with the Na,K-ATPase system in vascular smooth muscle cells wa...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.53.2.186
更新日期:1983-08-01 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.114.302721
更新日期:2014-06-06 00:00:00
abstract::To test the hypothesis that early interventional treatment with insulin-like growth factor-1 (IGF-1) alleviates subsequent development of dilated cardiomyopathy, cardiac-specific IGF-1 expression was introduced by selective cross-breeding into a transgenic mouse model of heart failure that displays phenotypic characte...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.0000013780.77774.75
更新日期:2002-04-05 00:00:00
abstract:RATIONALE:In normal and diseased vascular smooth muscle (SM), the RhoA pathway, which is activated by multiple agonists through G protein-coupled receptors (GPCRs), plays a central role in regulating basal tone and peripheral resistance. This occurs through inhibition of myosin light chain phosphatase, leading to incre...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.111.248898
更新日期:2011-10-14 00:00:00
abstract::CD40 is a 48-kDa phosphorylated transmembrane glycoprotein belonging to the TNF receptor superfamily. CD40 has been demonstrated on a range of cell types, and it has an important role in adaptive immunity and inflammation. CD40 has recently been described on platelets but platelet activation by CD40 has not been descr...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000070111.98158.6C
更新日期:2003-05-16 00:00:00
abstract::Genome-wide association studies have uncovered over a 100 genetic loci associated with atrial fibrillation (AF), the most common arrhythmia. Many of the top AF-associated loci harbor key cardiac transcription factors, including PITX2, TBX5, PRRX1, and ZFHX3. Moreover, the vast majority of the AF-associated variants li...
journal_title:Circulation research
pub_type: 评审
doi:10.1161/CIRCRESAHA.120.316574
更新日期:2020-06-19 00:00:00
abstract:RATIONALE:One of the physiological mechanisms by which the heart adapts to a rise in blood pressure is by augmenting myocyte stretch-mediated intracellular calcium, with a subsequent increase in contractility. This slow force response was first described over a century ago and has long been considered compensatory, but...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.111.256743
更新日期:2011-12-09 00:00:00
abstract::We determined the extent of convergence of preganglionic fibers from the right and left vagus nerves on postganglionic neurons that supply the sinoatrial node in chloralose-anesthetized dogs. We administered hemicholinium-3 and stimulated the right vagus nerve at a high frequency to deplete acetylcholine from the post...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.67.3.556
更新日期:1990-09-01 00:00:00
abstract::Nonlaminar flow is a major predisposing factor to atherosclerosis. Yet little is known regarding hemodynamic gene regulation in disease-prone areas of the vascular tree in vivo. We have determined spatial patterns of expression of endothelial cell receptors in the arterial tree and of reporter gene constructs in trans...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000111803.92923.D6
更新日期:2004-02-20 00:00:00
abstract::Over the last 4 decades, heart transplantation (HTx) has evolved as a mainstream therapy for heart failure. Approximately half of patients needing HTx have organ failure consequent to atherosclerosis. Despite advances in immunosuppressive drugs, long-term success of HTx is limited by the development of a particular ty...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/01.RES.0000246086.93555.f3
更新日期:2006-10-13 00:00:00
abstract::Sinus node recovery time was compared to the recovery time of a slow atrioventricular junctional rhythm in each of the same seven pentobarbital anesthetized dogs. Recovery time and the first five cardiac cycles were examined after pacing atria and ventricles for 20, 40, and 60 seconds at four or more pacing cycle leng...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.57.1.182
更新日期:1985-07-01 00:00:00
abstract::The predominant cardiac Ca2+/calmodulin-dependent protein kinase (CaMK) is CaMKIIdelta. Here we acutely overexpress CaMKIIdeltaC using adenovirus-mediated gene transfer in adult rabbit ventricular myocytes. This circumvents confounding adaptive effects in CaMKIIdeltaC transgenic mice. CaMKIIdeltaC protein expression a...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000200739.90811.9f
更新日期:2006-02-03 00:00:00
abstract::We measured pressure-volume curves in nine excised dog ventricles and stress-strain curves in two to five muscle specimens from each ventricle to verify a derived formula that relates muscle stiffness to the ventricular pressure-volume curve. The assumptions underlying this formula are: (1) the ventricle is a uniform ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.37.6.787
更新日期:1975-12-01 00:00:00
abstract::By using excised postmortem hearts obtained from 15 mongrel dogs with the pericardium intact, we investigated mechanical interactions between the four heart chambers from the standpoint of ventricular pressure-volume relationships. The interactions investigated were those between (1) the atrium and the ventricle, (2) ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.50.1.86
更新日期:1982-01-01 00:00:00
abstract::We performed morphological studies of myocardial contracture to define its nature and relationship to mechanical changes occurring during metabolic blockade. Isolated rat papillary and trabecular muscles were stretched to the apices of their length-tension curves and stimulated to contract isometrically 12 times a min...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.45.2.298
更新日期:1979-08-01 00:00:00
abstract::Effects of concentrations of intracellular calcium, [Ca2+]i, on the voltage-dependent Ca2+ current (ICa) recorded from dispersed single smooth muscle cells of the rabbit portal vein were studied, using a whole cell voltage clamp method combined with an intracellular perfusion technique. Outward currents were minimized...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.62.2.375
更新日期:1988-02-01 00:00:00
abstract::The use of risk markers has transformed cardiovascular medicine, exemplified by the routine assessment of troponin, for both diagnosis and assessment of prognosis in patients with chest pain. Clinical risk factors form the basis for risk assessment of cardiovascular disease and the addition of biochemical, cellular, a...
journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.116.309955
更新日期:2017-01-06 00:00:00
abstract::Angiotensin II (Ang II) increases renal sympathetic nerve activity in anesthetized mice before and after ganglionic blockade, suggesting that Ang II may directly activate postganglionic sympathetic neurons. The present study directly tested this hypothesis in vitro. Neurons were dissociated from aortic-renal and celia...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/hh0801.089542
更新日期:2001-04-27 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:RATIONALE:Elevations in C-reactive protein (CRP) are associated with increased cardiovascular disease risk and endothelial dysfunction. CRP antagonizes endothelial nitric oxide synthase (eNOS) through processes mediated by the IgG receptor Fcγ receptor IIB (FcγRIIB), its immunoreceptor tyrosine-based inhibitory motif, ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.111.254573
更新日期:2011-10-28 00:00:00
abstract::Cardiac and arterial tissues of six male and six female adult baboons were examined for nuclear uptake of tritiated 5-alpha-dihydrotestosterone (3H-DHT) or tritiated estradiol-17 beta (3H-E2) by autoradiography. 3H-DHT uptake occurred in nuclei of most atrial and ventricular myocardial fibers, no cardiac interstitial ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.48.2.238
更新日期:1981-02-01 00:00:00
abstract::Elevated plasma levels of plasminogen activator inhibitor type I (PAI-1), a significant risk factor of ischemic heart disease, are associated with insulin resistance in which insulin and transforming growth factor (TGF)-beta play a pivotal role in regulating PAI-1 production. Forkhead transcription factor FOXC2 is an ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000207407.51752.3c
更新日期:2006-03-17 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::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::Inwardly rectifying K+ (Kir) channels are responsible for maintaining endothelial membrane potential and play a key role in endothelium-dependent vasorelaxation. In this study, we show that endothelial Kir channels are suppressed by hypercholesterolemic levels of lipoproteins in vitro and by serum hypercholesterolemia...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000218776.87842.43
更新日期:2006-04-28 00:00:00