Abstract:
:Net cellular L-lactate efflux associated with accelerated anaerobic glycolysis has been implicated as a potential cause of the marked cellular K+ loss contributing to lethal cardiac arrhythmias in ischemic heart and to impaired function of fatigued skeletal muscle. To examine the mechanisms of transsarcolemmal L-lactate movement in the heart, isolated guinea pig ventricular myocytes were loaded with the fluorescent H+ or K+ indicators, carboxy SNARF-1 or PBFI, respectively, under whole-cell patch-clamp conditions. With H+ as the only permeable monovalent cation, a rapid increase in extracellular L-lactate concentration ([L-]o) from 0 to 30 mmol/L at constant pHo (7.35) caused an intracellular acidification averaging 0.18 +/- 0.02 pH units in 60 seconds (n = 7), reflecting L-lactate influx in association with H+ influx (or OH- efflux). Under voltage-clamp conditions, no significant electrogenic current was associated with H(+)-coupled L-lactate influx, and membrane potential (-75 to +75 mV) had no effect on the degree of acidification produced by 30 mmol/L [L-]o, indicating that L-lactate influx was predominantly nonelectrogenic. Acidification in response to increased [L-]o was saturable (Km, approximately 5 mmol/L), partially stereospecific for L-lactate over D-lactate, and inhibited by 55 +/- 7% and 82 +/- 7% by the monocarboxylate carrier inhibitors alpha-cyano-4-hydroxycinnamate and mersalyl acid, respectively, consistent with a carrier-mediated transport mechanism. Extracellular K+ inhibited H(+)-coupled L-lactate influx by 36 +/- 2%, suggesting that K+ either inhibited or substituted for H+ in cotransport with L-lactate. However, in myocytes loaded with PBFI, no significant increase in [K+]i was detected during exposure to 30 mmol/L [L-]o, suggesting that only a minor component, if any, of L-lactate influx was cotransported or codiffused with K+.
journal_name
Circ Resjournal_title
Circulation researchauthors
Shieh RC,Goldhaber JI,Stuart JS,Weiss JNdoi
10.1161/01.res.74.5.829subject
Has Abstractpub_date
1994-05-01 00:00:00pages
829-38issue
5eissn
0009-7330issn
1524-4571journal_volume
74pub_type
杂志文章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::The effects of two types of repeated transient coronary artery occlusions on collateral development were examined in chronically instrumented, conscious dogs. A 2-minute coronary occlusion at 32-minute intervals (group 1, n = 11) or a 15-second occlusion at 4-minute intervals (group 2, n = 7) were repeated day and nig...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.64.2.287
更新日期:1989-02-01 00:00:00
abstract::We created knock-in mice in which a deletion of 3 base pairs coding for K210 in cardiac troponin (cTn)T found in familial dilated cardiomyopathy patients was introduced into endogenous genes. Membrane-permeabilized cardiac muscle fibers from mutant mice showed significantly lower Ca(2+) sensitivity in force generation...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.106.146670
更新日期:2007-07-20 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
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journal_title:Circulation research
pub_type: 杂志文章,评审
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更新日期:2015-06-05 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.64.2.407
更新日期:1989-02-01 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/hh0402.105956
更新日期:2002-03-08 00:00:00
abstract:RATIONALE:Abnormal phenotypic switch of vascular smooth muscle cell (VSMC) is a hallmark of vascular disorders such as atherosclerosis and restenosis after angioplasty. MicroRNAs (miRNAs) have emerged as important regulators for VSMC function, and we recently identified miR-663 as critical for controlling human aortic ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.113.301306
更新日期:2013-10-25 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.72.2.424
更新日期:1993-02-01 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.83.3.279
更新日期:1998-08-10 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.119.315786
更新日期:2019-10-25 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.RES.0000189259.69645.25
更新日期:2005-11-11 00:00:00
abstract::Myocardial damage due to reperfusion of ischemic tissue is caused primarily by infiltrating neutrophils. Although leukocyte beta2 integrins (CD18) play a critical role, significant neutrophil emigration persists when CD18 is neutralized or absent. This study examined the role of leukocyte beta1 integrin (alpha4) and i...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.0000013835.53611.97
更新日期:2002-03-22 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.55.6.740
更新日期:1984-12-01 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.110.238717
更新日期:2011-07-08 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.79.3.461
更新日期:1996-09-01 00:00:00
abstract::The objective of this study was to elucidate the mechanisms associated with the reciprocal relation between magnesium and calcium on vascular smooth muscle tone in bovine pulmonary artery and vein. Rapid removal of magnesium from Krebs-bicarbonate medium used to bathe isolated rings of precontracted artery or vein cau...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.66.2.355
更新日期:1990-02-01 00:00:00
abstract::It is believed that inotropic agents exert their effects in cardiac muscle via a modulation of Ca2+ cycling; however, the involvement of phospholipase activation and the biochemical pathways participating in inotropic responsiveness remain unclear. The aim of the current study was to determine whether arachidonic acid...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.72.2.376
更新日期:1993-02-01 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/CIRCRESAHA.111.243956
更新日期:2012-06-08 00:00:00
abstract::Postischemic endothelial dysfunction may occur as a result of the effects of endogenous oxidants like hydrogen peroxide. Since endothelium-dependent vasodilator function may be affected by pHi, the effect of hydrogen peroxide on endothelial pHi was examined. Hydrogen peroxide (100 micromol/L for 10 minutes) decreased ...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.83.6.644
更新日期:1998-09-21 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章,评审
doi:10.1161/01.RES.0000127122.22685.0A
更新日期:2004-05-14 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.86.12.1211
更新日期:2000-06-23 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.82.12.1243
更新日期:1998-06-29 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/CIRCRESAHA.113.300350
更新日期:2013-03-15 00:00:00
abstract::Some statistical techniques for analyzing the kinds of studies typically reported in Circulation Research are described. Particular emphasis is given to the comparison of means from more than two populations, the joint effect of several experimentally controlled variables, and the analysis of studies with repeated mea...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.47.1.1
更新日期:1980-07-01 00:00:00
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.68.1.300
更新日期:1991-01-01 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
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journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.83.5.568
更新日期:1998-09-07 00:00:00
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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::The activity of the adrenergic system plays an important role in the genesis of malignant arrhythmias and the spreading of the infarcted zone in acute myocardial ischemia. Acute myocardial ischemia induces an increased activity of adenylyl cyclase. This sensitization at the enzyme level as shown in the isolated perfus...
journal_title:Circulation research
pub_type: 杂志文章
doi:10.1161/01.res.70.6.1304
更新日期:1992-06-01 00:00:00