Abstract:
:Myocytes isolated from guinea pig ventricles were voltage-clamped using patch pipettes in the whole-cell configuration. For proper voltage control fast Na+ current was blocked by TTX or inactivated by an appropriate prepulse. Zero-load cell shortening was monitored by a photoelectric device. The mechanical response to a short depolarizing clamp was mainly a phasic (transient) contraction. Long-lasting depolarizations caused a tonic (sustained) shortening of a cell. Different clamp patterns were used to study the mode of activation of phasic contraction. 1) With a constant Ca2+ preload established by a train of conditioning pulses, the shortening-voltage relation measured with test pulses of varying height was a bell-shaped curve reflecting the slow inward current (ICa)-voltage relation. The test pulse had a striking influence on the first contraction of the following conditioning series, resulting in an S-shaped relation between post-test contraction and test potential. 2) With series of identical clamps of varying height, steady-state contraction was maximal around 40 mV and not in proportion to ICa. In these measurements Ca2+ preload was likely to increase with increasing potential. It is concluded that ICa initiates phasic contraction by inducing a release of Ca2+ from internal stores while replenishment of the stores is largely determined by an electrogenic transsarcolemmal Na+-Ca2+ exchange. The data suggest that Na+-Ca2+ exchange is not only involved in long-term changes of cardiac contractility but also in beat-to-beat regulation.
journal_name
Basic Res Cardioljournal_title
Basic research in cardiologyauthors
Meyer R,Haas HG,Wiemer Jdoi
10.1007/BF01907923subject
Has Abstractpub_date
1989-03-01 00:00:00pages
136-48issue
2eissn
0300-8428issn
1435-1803journal_volume
84pub_type
杂志文章abstract::Atherosclerotic plaque rupture is the key event in the pathogenesis of acute coronary syndromes and it also occurs during coronary interventions. Atherosclerotic plaque rupture does not always result in complete thrombotic occlusion of the epicardial coronary artery with subsequent impending myocardial infarction, but...
journal_title:Basic research in cardiology
pub_type: 杂志文章,评审
doi:10.1007/s00395-006-0616-1
更新日期:2006-09-01 00:00:00
abstract::Myocardial stunning, a transient contractile dysfunction that appears following a brief period of ischemia, is at least partly due to the production of oxygen-derived free radicals. The objective of the present study was to determine whether the Ginkgo biloba extract EGb761, which has antioxidant properties in vitro, ...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/s00395-003-0380-4
更新日期:2003-02-01 00:00:00
abstract::An increase in extracellular potassium concentration from 4 to 16 mmol/l caused a decrease in membrane potential from -92 to -59 mV and selectively diminished the earlier of two contraction components of guinea-pig papillary muscles at 0.2 Hz stimulation frequency in the presence of noradrenaline. The influence on the...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF01907089
更新日期:1987-09-01 00:00:00
abstract::The article describes a method for monitoring the total energy output and oxygen uptake of isolated perfused rat hearts with working left ventricles. Twenty-two unpaced hearts (rates 4-4.5 bs-1) were separately investigated inside a flow micro-calorimeter (one minute for 90% thermal response) at 37 degrees C. They pum...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF01907920
更新日期:1985-09-01 00:00:00
abstract::Cardiac mass, cell size and capillary supply were studied in the hearts of spontaneously hypertensive rats (SHR) and compared to genetically similar non-hypertensive Wistar-Kyoto (WKY) of three adult ages: 5, 15 and 23 months. The left ventricular weight of SHR was not significantly greater than that of WKY at 5 month...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF01908138
更新日期:1984-07-01 00:00:00
abstract::The hormone-sensitive adenylate cyclase is a multi-component system embedded in the lipid bilayer of the plasma membrane and serves as a signal transduction system for various membrane receptors. The complete system consists of various receptor molecules, which sensitize the external ligands, the effector enzyme adeny...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF01907422
更新日期:1986-01-01 00:00:00
abstract::For 219 children between 3 and 15 years with the most frequent congenital and acquired heart failures it was investigated in what way the STI differ consistently from the corresponding standard values. It was found that all the STI of children with cardiovascular diseases can vary from the normal values scaled by hear...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF01906520
更新日期:1978-07-01 00:00:00
abstract::The cardiac renin angiotensin system (RAS) is the target for number of therapeutic interventions which proved successful in heart failure. Angiotensin converting enzyme (ACE) inhibitors belong to the most efficient strategies available and angiotensin receptor (ATR) antagonists may be comparably effective. The direct ...
journal_title:Basic research in cardiology
pub_type: 杂志文章,评审
doi:10.1007/s003950050207
更新日期:1998-01-01 00:00:00
abstract::Elucidation of the subcellular mechanism of myocardial ischemic preconditioning should be facilitated by precise knowledge of the biology of the cardioprotective response. Any proposed molecular mechanism for preconditioning must be initiated during the required ischemic stress period. The studies reported in this pap...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF00805571
更新日期:1997-04-01 00:00:00
abstract::Receptor for advanced glycation end products (RAGE) is associated with inflammation and the progression of cardiovascular diseases. The current study tested the hypothesis that RAGE is involved in the pathogenesis of aortic valve (AV) calcification. Pioglitazone attenuated AV calcification in experimental hypercholest...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/s00395-012-0306-0
更新日期:2012-11-01 00:00:00
abstract::The ability of the rhesus monkey to form coronary collaterals was tested in ten animals. Ameroid constrictors were implanted on the left circumflex coronary artery and allowed to remain for 12 weeks. One animal died of an acute myocardial infarction nine days after surgery; the remaining animals survived without clini...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF01906462
更新日期:1983-09-01 00:00:00
abstract::Hypertension and resulting left ventricular hypertrophy was induced in young male Wistar rats (60 to 70 days old) by narrowing of one renal artery (Goldblatt II). 8 and 24 weeks after operation, myocardial oxygen consumption was measured on a modified in situ heart-lung preparation with nearly isovolumetric left ventr...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF01908041
更新日期:1982-05-01 00:00:00
abstract::In open-chest pigs during severe myocardial ischemia [K+]e, [Ca2+]e and [H+]e increase, [Na+]e increases transiently reaching control values after 30 min. Extracellular osmolality of the ischemic area increases due to an H2O-shift from the ECS to the ICS. The increase of [Na+]e and [Ca2+]e must b explained by the shri...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF01908341
更新日期:1981-07-01 00:00:00
abstract::The hypothesis was tested that vardenafil, a PDE5 inhibitor, specifically enhances coronary vasodilation during acidosis. In isolated constant pressure perfused guinea pig hearts, infusion of vardenafil ( journal_title:Basic research in cardiology pub_type: 杂志文章 doi:10.1007/s00395-006-0630-3 更新日期:2007-03-01 00:00:00
abstract::The purpose of this study was to determine the effects of bradykinin (BK), substance P (SP) and histamine on plasma exudation in the skin of conscious dogs with and without pacing-induced heart failure. We also determined the role tissue angiotensin I-converting enzyme (ACE) and neutral endopeptidase (NEP) play in mod...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF00788284
更新日期:1994-09-01 00:00:00
abstract::Apart from local heterogeneities of myocardial blood flow, the regulation of vascular tone is equally complex. Changes in vascular tone are essential for the adaptation of coronary blood flow to varying metabolic demands. The majority of coronary vascular resistance is found in the microcirculation, that is, in vessel...
journal_title:Basic research in cardiology
pub_type: 杂志文章,评审
doi:10.1007/s003950050114
更新日期:1998-12-01 00:00:00
abstract::The effect of 0.1 mg/kg Verapamil on the extent of the ischemic area following ligation of a branch of the left descending coronary artery was studied in anesthetized open chest dogs. The sum of the ST-segment elevation during the entire period of occlusion in the epicardial ECG was 15 mV in control infarction compare...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF01905620
更新日期:1975-03-01 00:00:00
abstract::Exercise is an efficient strategy for myocardial protection against ischemia-reperfusion (IR) injury. Although endothelial nitric oxide synthase (eNOS) is phosphorylated and activated during exercise, its role in exercise-induced cardioprotection remains unknown. This study investigated whether modulation of eNOS acti...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/s00395-013-0389-2
更新日期:2013-11-01 00:00:00
abstract::Thyroid hormone (TH) is critical for tissue differentiation at early stages of development, induces physiological hypertrophy and regulates the expression of important contractile proteins such as myosin heavy chain (MHC) isoform and calcium cycling proteins. Furthermore, TH seems to control the response to stress by ...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/s00395-008-0697-0
更新日期:2008-07-01 00:00:00
abstract::Disregarding the influence of thickness on elevated strength of isolated preparations inevitably leads to erroneous tension-frequency relations, especially in the range of high frequencies. Thus, much of the confusion in interpreting the atypical negative staircase phenomenon of the rat heart is due to this. In view o...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/978-3-662-11289-2_25
更新日期:1987-01-01 00:00:00
abstract::Delta-opioid receptors are known to participate in the protection found following ischemic preconditioning (IPC), but the role of kappa-receptors in IPC is currently controversial. Langendorff-perfused rat hearts received 35 min regional ischemia and 2 h reperfusion. PC (2 cycles 5 min global ischemia) substantially r...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/s003950050001
更新日期:2000-02-01 00:00:00
abstract::We tested the hypotheses that myocardial infarction in mice would lead to progressively worsening heart failure 12-18 weeks later and that exercise testing would provide a suitable means to evaluate left ventricular function sequentially. C57BL/6 mice (n = 69) underwent left coronary artery ligation (n = 50) or thorac...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/s003950200013
更新日期:2002-05-01 00:00:00
abstract::This paper reviews the recent data concerning the force-frequency relations in experimental animals with heart failure. After a brief overview of the nature of these relations, which are induced by 2 opposite phenomena, the potentiation of force of contraction by heart rate and the restitution process, the paper revie...
journal_title:Basic research in cardiology
pub_type: 杂志文章,评审
doi:10.1007/s003950050212
更新日期:1998-01-01 00:00:00
abstract::Increase of Ca2+ concentration to 7.5 mM in the presence of 10 mM or 20 mM caffeine shifted length-tension relationships of 5 rat trabecular muscles and 5 cat papillary muscles to higher tensions. At 1max diastolic tension was enhanced from (formula: see text), for all measured points of stress-strain relationships af...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF01906525
更新日期:1978-09-01 00:00:00
abstract::PDE3 cyclic nucleotide phosphodiesterase inhibitors raise cAMP and cGMP content in cardiac and vascular myocytes. Their administration to patients with dilated cardiomyopathy leads to improvements in hemodynamic parameters in the short term but reduces survival with chronic administration. The reasons for this 'biphas...
journal_title:Basic research in cardiology
pub_type: 杂志文章,评审
doi:10.1007/s003950200035
更新日期:2002-01-01 00:00:00
abstract::An orifice equation for the non-invasive measurement of mitral-valve area is demonstrated. It is shown that by combining this expression with the assumption of mitral-valve area invariance an orifice equation for the non-invasive assessment of cardiac output in conditions of mitral stenosis using simple echographicall...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF01923191
更新日期:1983-01-01 00:00:00
abstract:AIMS:We studied the capability of heart rate (HR) adjusted change in multichannel magnetocardiogram (MCG) to detect exercise-induced ischemia. METHODS AND RESULTS:The MCG and 12-lead ECG were recorded simultaneously during supine exercise testing in 17 healthy controls and 24 patients with single vessel coronary arter...
journal_title:Basic research in cardiology
pub_type: 临床试验,杂志文章
doi:10.1007/s395-002-8391-y
更新日期:2002-01-01 00:00:00
abstract::The available data clearly suggest large alterations in myocardial eicosanoid generation during myocardial ischaemia and demonstrate important actions of eicosanoids on myocardial function during ischaemic conditions. These actions include direct effects on the injured myocardium as well as influences on other target ...
journal_title:Basic research in cardiology
pub_type: 杂志文章,评审
doi:10.1007/978-3-662-08390-1_27
更新日期:1987-01-01 00:00:00
abstract::Previous studies indicated that the increase in protein kinase C (PKC)-mediated myofilament protein phosphorylation observed in failing myocardium might be detrimental for contractile function. This study was designed to reveal and compare the effects of PKCalpha- and PKCepsilon-mediated phosphorylation on myofilament...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/s00395-009-0053-z
更新日期:2010-03-01 00:00:00
abstract::Toxic peroxides result when oxygen radicals react with various peroxidic precursors in tissue or blood. A colorimetric method based on reactions of malondialdehyde (MDA), a key intermediate in the formation of peroxides, has been described in fresh tissues. The present report adapts this assay to measure MDA levels in...
journal_title:Basic research in cardiology
pub_type: 杂志文章
doi:10.1007/BF01910480
更新日期:1984-09-01 00:00:00