Abstract:
:The fluorescent dye 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF) was used to measure pHi in the spontaneously hypertensive rat (SHR) and in normal rat cardiac myocytes under nominally HCO3-free (20 mmol/L HEPES-buffered) conditions. When only the Na-H exchanger was blocked, the intrinsic buffering power (beta i) in SHR myocytes was significantly higher than when both the Na-H exchanger and 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS)-sensitive pHi regulators (the Na-HCO3 cotransporter and the Cl-HCO3 exchanger) were blocked. Similar low values for beta i were also found for normal rat myocytes in Na(+)-free conditions. In Cl(-)-free solution under nominally HCO3-free conditions, in both normal and SHR myocytes, the pHi slowly alkalinized (by 0.16 +/- 0.02 and 0.11 +/- 0.02 pH units, respectively); this alkalinization was also DIDS sensitive. The reacidification during NH4+ perfusion was inhibited 30.2 +/- 7.4% by DIDS. In addition, in the nominal absence of HCO3-, 100 mumol/L ATP acidified the pHi in both normal and SHR myocytes (by 0.21 +/- 0.03 and 0.33 +/- 0.03 pH units, respectively); this acidification was totally inhibited by 0.1 mmol/L DIDS. It has been shown, in rat cardiac myocytes, that ATP acidifies the pHi by 0.35 pH unit via stimulation of a DIDS-sensitive Cl-HCO3 exchanger in HCO3-containing solutions. Finally, we have shown, in normal cardiac myocytes, that two potent Na-H exchanger blockers, N-5-ethylisopropyl amiloride (EIPA) and N-5-methyl-N-isobutyl amiloride (MIA), only partially inhibited the pHi recovery from internal acidosis under nominally bicarbonate-free conditions. When DIDS was added at the same time as EIPA, pHi recovery from an internal acid loading was completely inhibited. Our results clearly demonstrate that in both normal and SHR cardiac myocytes, bicarbonate-dependent pHi regulators can be significantly activated under resting or acidified pHi in HEPES-buffered medium, probably because of the cellular production of CO2. The contribution of these bicarbonate-dependent pHi regulators, ie, the Na-HCO3 cotransporter and the Cl-HCO3 exchanger, cannot therefore be ignored even under nominally HCO3-free conditions.
journal_name
Circ Resjournal_title
Circulation researchauthors
Wu ML,Tsai ML,Tseng YZdoi
10.1161/01.res.75.1.123subject
Has Abstractpub_date
1994-07-01 00:00:00pages
123-32issue
1eissn
0009-7330issn
1524-4571journal_volume
75pub_type
杂志文章abstract::To study the effects of stretch on the function of rat left atrium, we recorded contraction force, calcium transients, and intracellular action potentials (APs) during stretch manipulations. The stretch of the atrium was controlled by intra-atrial pressure. The Frank-Starling behavior of the atrium was manifested as a...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.83.11.1165
更新日期:1998-11-30 00:00:00
abstract::Hemodynamic shear stress elicits a rise in endothelial [Ca2+]i, which may serve as a key second messenger to regulate many flow-associated physiological and biochemical processes. In the present study, we used Mn2+ quenching of fluorescent dye Fluo3 as an assay to investigate the Ca2+ influx of rat aortic endothelial ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.0000054625.24468.08
更新日期:2003-02-21 00:00:00
abstract::Increases in free Mg2+ from 0.04 to 10.0 mM with constant pH 7.0 TO 0.10 M ionic strength, and 2 mM MgATP2- caused a rightward shift of the free Ca-relative ATPase relation for both cardiac skeletal myofibrils. The specific activity of cardiac myofibrillar ATPase over a wide range of free Ca2+ was, however, depressed ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.39.1.8
更新日期:1976-07-01 00:00:00
abstract:RATIONALE:Depletion of medial smooth muscle cell (SMC) is a major pathological characteristic of abdominal aortic aneurysm (AAA), although the mechanism by which these cells are eliminated remains incompletely understood. We reasoned that necroptosis, a recently described form of necrosis mediated by receptor-interacti...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.116.304899
更新日期:2015-02-13 00:00:00
abstract::The signaling pathways involved in the long-term metabolic effects of angiotensin II (Ang II) in vascular smooth muscle cells are incompletely understood but include the generation of molecules likely to affect oxidase activity. We examined the ability of Ang II to stimulate superoxide anion formation and investigated...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.74.6.1141
更新日期:1994-06-01 00:00:00
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, dihydro...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.56.2.231
更新日期:1985-02-01 00:00:00
abstract::AR-L 115BS, a benzimidazole derivative, is a positive inotropic agent that has been shown to increase active tension development and unloaded shortening velocity of chemically skinned heart muscle preparations at submaximal activating levels of free Ca++. We measured the effect of AR-L on relations between free Ca++, ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.51.3.290
更新日期:1982-09-01 00:00:00
abstract::After cervical aortic nerve section, mean arterial pressure in the unanesthetized dog increased by an average of 7.4 mm Hg. Following a more extensive denervation of aortic arch receptors by section of intrathoracic vagal branches, arterial pressure increased by 16.7 mm Hg. The above changes were seen in the stable st...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.45.1.26
更新日期:1979-07-01 00:00:00
abstract::We report the cloning of cDNAs encoding two different human nonmuscle myosin heavy chains designated NMMHC-A and NMMHC-B. The mRNAs encoding NMMHC-A and NMMHC-B are both 7.5 kb in size but are shown to be the products of different genes, which are localized to chromosome 22q11.2 and chromosome 17q13, respectively. In ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.69.2.530
更新日期:1991-08-01 00:00:00
abstract::This report evaluates pulse wave propagation with respect to contributions by vascular wall elastic and geometric properties, vessel wall and blood viscosity, and nonlinearities in system parameters and in the equations of motion. Discrepancies in results obtained with different experimental methods and theory are dis...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.49.2.442
更新日期:1981-08-01 00:00:00
abstract::This study was performed to examine, first, the protective effects and responses of collateral vessels of the hind limb in normal and atherosclerotic monkeys and, second, the effects of chronic arterial occlusion on the development of atherosclerosis. The iliac artery was ligated on one side in cynomolgus monkeys. Six...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.63.6.1020
更新日期:1988-12-01 00:00:00
abstract:RATIONALE:Adoptive transfer of cardiac progenitor cells (CPCs) has entered clinical application, despite limited mechanistic understanding of the endogenous response after myocardial infarction (MI). Extracellular matrix undergoes dramatic changes after MI and therefore might be linked to CPC-mediated repair. OBJECTIV...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.113.301152
更新日期:2013-07-05 00:00:00
abstract::Lipopolysaccharide (LPS) causes endothelial cell injury both in vitro and in vivo. It is widely believed that this injury in vivo enhances the transport of macromolecules from plasma into the interstitial space of the underlying artery wall. A new technique was used in rats to obtain high resolution transmural profile...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.68.5.1259
更新日期:1991-05-01 00:00:00
abstract:RATIONALE:Hydrogen peroxide (H(2)O(2)) serves as a key endothelium-derived hyperpolarizing factor mediating flow-induced dilation in human coronary arterioles (HCAs). The precise mechanisms by which H(2)O(2) elicits smooth muscle hyperpolarization are not well understood. An important mode of action of H(2)O(2) involve...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.111.258871
更新日期:2012-02-03 00:00:00
abstract::Therapeutic angiogenesis using vascular endothelial growth factor (VEGF) is considered a promising new therapy for patients with arterial obstructive disease. Clinical improvements observed consist of improved muscle function and regression of rest pain or angina. However, direct evidence for improved vascularization,...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000133247.69803.c3
更新日期:2004-07-09 00:00:00
abstract::Although vascular endothelial growth factor (VEGF) has been described as a potent angiogenic stimulus, its application in therapy remains difficult: blood vessels formed by exposure to VEGF tend to be malformed and leaky. In nature, the principal form of VEGF possesses a binding site for ECM components that maintain i...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000126411.29641.08
更新日期:2004-04-30 00:00:00
abstract:RATIONALE:Post-myocardial infarction ventricular remodeling is associated with the expression of a variety of factors including S100B that can potentially modulate myocyte apoptosis. OBJECTIVE:This study was undertaken to investigate the expression and function of S100B and its receptor, the receptor for advanced glyc...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.109.195834
更新日期:2010-01-08 00:00:00
abstract::Intracellular recordings were made from eustachian ridge of cat right atrium to determine mechanisms responsible for subsidiary pacemaker automaticity. Pacemaker action potentials exhibited two phases of diastolic depolarization: an initial steeper slope (D1) followed by a more gradual slope (D2). Cesium (1 mM) decrea...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.64.4.648
更新日期:1989-04-01 00:00:00
abstract:RATIONALE:Mammalian cardiomyocytes withdraw from the cell cycle during early postnatal development, which significantly limits the capacity of the adult mammalian heart to regenerate after injury. The regulatory mechanisms that govern cardiomyocyte cell cycle withdrawal and binucleation are poorly understood. OBJECTIV...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.111.248880
更新日期:2011-09-02 00:00:00
abstract::To investigate the relation of pressure and vascular wall thickening in hypertension, we coarcted the abdominal aorta upstream to the renal arteries in 14 rats. Sham-coarcted (n = 16) and two-kidney, one-clip (Goldblatt) hypertensive rats (n = 13) served as controls. Tail, femoral, and carotid arterial pressures rose ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.62.5.1001
更新日期:1988-05-01 00:00:00
abstract::Phenotypic switching of vascular smooth muscle cells (VSMCs) is known to play a critical role in the development of atherosclerosis. However, the factors present within lesions that mediate VSMC phenotypic switching are unclear. Oxidized phospholipids (OxPLs), including 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosp...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.108.186064
更新日期:2009-03-13 00:00:00
abstract::3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) can exert beneficial effects independently of serum cholesterol reduction by increasing the bioavailability of nitric oxide. However, it is unclear whether statins can exert such effects directly on cardiac myocytes and whether mitochondria...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000097262.21507.DF
更新日期:2003-10-17 00:00:00
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 ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.65.5.1161
更新日期:1989-11-01 00:00:00
abstract::Bradykinin relaxes arterioles on the brain's surface. This response is endothelium-dependent. The data presented here confirm the hypothesis that hydroxyl free radical mediates this response and may be the endothelium-dependent relaxing factor for bradykinin in this microvascular bed. The response to a locally applied...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.61.4.601
更新日期:1987-10-01 00:00:00
abstract::The extracellular and intracellular potassium (K+) activities of isolated superfused rabbit atrial muscle were measured using K+-sensitive liquid ion exchanger microelectrodes. When the pH of the bathing medium was decreased from 7.5 to 6.8, intracellular K+ activity fell and extracellular K+ activity rose from a mean...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.39.5.678
更新日期:1976-11-01 00:00:00
abstract::The contractile response of the aged adult heart to beta-adrenergic stimulation is known to be reduced compared with the young adult heart. Since endogenous adenosine exerts an antiadrenergic action in the heart, this study was undertaken to determine if the basal endogenous level of myocardial adenosine increases wit...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.66.5.1381
更新日期:1990-05-01 00:00:00
abstract::Tissue factor (TF) is a low-molecular-weight glycoprotein that initiates the extrinsic clotting cascade and is considered a major regulator of arterial thrombogenicity. TF pathway inhibitor (TFPI) is a major physiological inhibitor of TF-initiated coagulation. The aim of this study was to define the complex interplay ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/hh1301.092508
更新日期:2001-07-06 00:00:00
abstract::The isolated rat heart perfused with washed platelets was used as a model to examine platelet-vessel wall interactions. Release of prostacyclin and thromboxane A2 was measured, using a cascade of smooth muscle bioassay tissues or radioimmunoassays of the stable hydration products. In hearts perfused with rabbit or hum...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.58.1.172
更新日期:1986-01-01 00:00:00
abstract::The SCN5A gene encodes the alpha subunit of the human heart sodium channel (hH1), which plays a critical role in cardiac excitability. Mutations of SCN5A underlie Brugada syndrome, an inherited disorder that leads to ventricular fibrillation and sudden death. This study describes changes in cellular localization and f...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/hh1201.093270
更新日期:2001-06-22 00:00:00
abstract::Magnesium modulates vascular smooth muscle cell (VSMC) function. However, molecular mechanisms regulating VSMC Mg2+ remain unknown. Using biochemical, pharmacological, and genetic tools, the role of transient receptor potential membrane melastatin 7 (TRPM7) cation channel in VSMC Mg2+ homeostasis was evaluated. Rat, m...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000152967.88472.3e
更新日期:2005-02-04 00:00:00