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 of the fact that the rat has become the preferred laboratory animal in cardiological research, it was imperative to reinvestigate force-frequency relations using ultra-thin preparations of the rat right ventricle (d less than 0.1 mm). Contrary to popular opinion, it could be demonstrated that the rat myocardium shows a positive staircase in the range of physiological heart rates. An increase in tension is still attainable even at frequencies up to 600 min-1. The interval-strength relations exhibit a minimum at frequencies of 60-120 min-1, being shifted to higher frequencies with increasing diameter, vanishing completely for thick preparations (d greater than 1.0 mm). At high extracellular Ca++ concentration the positive staircase even of ultra-thin muscles is flattened. However, it can be reinforced when the strength, and thus the energy expenditure, is reduced by lowering the extension. The same is true for contractions under hypoxia. From these findings it seems probable that many investigations on isolated heart muscles of the rat, as well as other species, are objectionable when done under high energy demand, as diffusion problems will certainly limit any rise in contractility.
journal_name
Basic Res Cardioljournal_title
Basic research in cardiologyauthors
Gülch RW,Ebrecht Gdoi
10.1007/978-3-662-11289-2_25subject
Has Abstractpub_date
1987-01-01 00:00:00pages
263-74eissn
0300-8428issn
1435-1803journal_volume
82 Suppl 2pub_type
杂志文章abstract：:We tested the hypothesis that in isolated cardiac myocytes, the negative functional effects of cyclic GMP would be blunted when the level of cyclic AMP was increased and that this interaction would be altered in renal hypertensive (One-Kidney-One-Clip, 1K1C) cardiac hypertrophic rabbits. Using isolated control and 1K1...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/s003950170075
更新日期：2001-02-01 00:00:00
abstract：:Age-related changes in the myocardial energy metabolism were studied in spontaneously hypertensive (SHR) rats of 5-15 weeks of age. Systolic blood pressure increased rapidly during 5 to 10 weeks of age (developing phase) and attained a plateau level at 10 to 15 weeks (sustained phase). Even during the developing phase...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/BF02005337
更新日期：1982-07-01 00:00:00
abstract：:Patients with insulin resistance and type 2 diabetes have poor cardiac outcomes following myocardial infarction (MI). The mitochondrial uncoupling protein 3 (UCP3) is down-regulated in the heart with insulin resistance. We hypothesized that decreased UCP3 levels contribute to poor cardiac recovery following ischemia/r...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/s00395-018-0707-9
更新日期：2018-10-29 00:00:00
abstract：:The relationship between ischemic contracture and no-reflow phenomenon was studied in 59 isolated rat hearts during global ischemia. The contracture was measured by a water-filled balloon catheter placed in the left ventricular lumen. The time of onset of contracture was changed by preischemic infusion with buffer con...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/BF02005340
更新日期：1982-07-01 00:00:00
abstract：:K201 has previously been shown to reduce diastolic contractions in vivo during β-adrenergic stimulation and elevated extracellular calcium concentration ([Ca(2+)](o)). The present study characterised the effect of K201 on electrically stimulated and spontaneous diastolic sarcoplasmic reticulum (SR)-mediated Ca(2+) rel...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/s00395-011-0218-4
更新日期：2011-11-01 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：OBJECTIVE:Cardiac stunning is the consequence of a brief cardiac ischemia. The underlying mechanism is not completely understood. METHODS:Here we induced cardiac transient ischemia in conscious instrumented dogs by means of an occluder in the left anterior descending coronary artery (LAD). Contractile performance, mon...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/s00395-005-0577-9
更新日期：2006-05-01 00:00:00
abstract：:Myocardial ischemia and infarction are the most common substrates for life-threatening ventricular tachyarrhythmias. Experimental and clinical evidence suggests that enhanced activity of the sympathetic nervous system plays an important role in the genesis of ischemia-related arrhythmias. In animal experiments, beta-b...
journal_title：Basic research in cardiology
pub_type： 杂志文章,评审
doi：10.1007/978-3-662-11038-6_24
更新日期：1990-01-01 00:00:00
abstract：:At 36 degrees C and 2 mM [Ca2+]o, single guinea-pig ventricular myocytes were voltage clamped with patch electrodes. When paired pulsing had potentiated the contraction to the maximum, the cells were shock-frozen for electron probe microanalysis (EPMA). Shock-freezing was timed at the end of diastole (-80 mV) or at di...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/978-3-662-30769-4_9
更新日期：1991-01-01 00:00:00
abstract：:It is shown that hypertrophied rat myocardium exhibits marked prolongation of its action potential during non-essential changes both in the resting potential, as well as in the amplitude of the action potential, and during a moderate but nonsignificant reduction in the maximum upstroke velocity. When examining action ...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/BF02001397
更新日期：1980-01-01 00:00:00
abstract：:A new experimental in-vitro model is described, which was used for studying prostacyclin (PGI2)-thromboxane A2 (TXA2)-interactions. Langendorff hearts of guinea pigs are perfused at constant volume with Krebs-Henseleit buffer and washed human platelets (4 x 10(8)/min). PGI2 and TXA2 release are measured by bioassay. T...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/BF01908344
更新日期：1981-09-01 00:00:00
abstract：:Hemodynamics and myocardial contractility were evaluated in five unanesthetized calves during acute hypocapnic and isocapnic hypoxia and during acute hypocapnic hypoxia with beta-adrenergic blockade. Both hypocapnic and isocapnic hypoxia, with mean PaO2 levels of 33.1 and 39.1 mm Hg respectively, produced a decline in...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/BF01909762
更新日期：1976-09-01 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：:We describe diastolic properties of the myocardium in terms of stress-strain relations. In a mathematical analysis, the equation sigma = alpha(e beta.epsilon-1) of the stress-strain curve can be changed by an increase in the exponent beta or the multiplicative constant alpha. It can be experimentally shown that in hyp...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/978-3-662-11289-2_26
更新日期：1987-01-01 00:00:00
abstract：:Isolated cells obtained from adult myocardium are proving invaluable for a wide range of studies concerned with the mechanisms underlying many important cardiological processes. Although care must always be taken to ensure that the single myocyte is an appropriate model for the particular question to be researched, it...
journal_title：Basic research in cardiology
pub_type： 杂志文章,评审
doi：
更新日期：1985-01-01 00:00:00
abstract：AIMS:A delayed myocardial protection extends between 24 and 96 h after ischemic preconditioning in animals. To test for this phenomenon in humans, subjects with stable angina were subjected to exercise test-induced myocardial ischemia and the effect of this "preconditioning" ischemic insult on the exercise-induced myoc...
journal_title：Basic research in cardiology
pub_type： 临床试验,杂志文章,随机对照试验
doi：10.1007/s003950070042
更新日期：2000-10-01 00:00:00
abstract：:The present study was designed to test the hypothesis that in hypertrophied myocardium of patients with hypertrophic obstructive cardiomyopathy (HOCM) a reduced contractile reserve provided by frequency dependent potentiation of force of contraction contributes to the myocardial dysfunction. Myectomy was performed in ...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/s003950050134
更新日期：1999-04-01 00:00:00
abstract：:There is a growing need for pharmacological agents to manage cardiovascular disease in the rapidly growing elderly population. Here, we determine if acetaminophen is efficacious in decreasing age-related increases in cardiac reactive oxygen species (ROS) and apoptosis in aging Fischer 344 X Brown Norway rats. Compared...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/s00395-010-0094-3
更新日期：2010-07-01 00:00:00
abstract：:Reperfusion following various intervals of coronary occlusion has produced conflicting results: increase in infarct size, especially with hemorrhage into the tissue, was reported as well as salvage of ischemic myocardium. To examine the problem and for the validation of our own method for infarct size measurement, whi...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/BF01907838
更新日期：1980-07-01 00:00:00
abstract：:Recent findings on the induction of anti-apoptotic gene expression in ischemic/reperfused hearts encouraged us to investigate whether ischemic/reperfused hearts may be protected against apoptosis induction. To analyze this hypothesis we performed studies on isolated perfused hearts of rat. For apoptosis induction, hea...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/s003950200053
更新日期：2002-11-01 00:00:00
abstract：:Ceramide has been shown to be a key signaling molecule involved in the apoptotic effect of tumor necrosis factor alpha (TNF-alpha) and other cytokines. Given the importance of cytokines such as TNF-alpha in myocardial ischemia-reperfusion injury, we hypothesize that ceramide is increased during ischemia or reperfusion...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/s003950170057
更新日期：2001-05-01 00:00:00
abstract：:Coronary artery disease (CAD), also known as ischemic heart disease (IHD), is the leading cause of mortality in the western world, with developing countries showing a similar trend. With the increased understanding of the role of the immune system and inflammation in coronary artery disease, it was shown that macropha...
journal_title：Basic research in cardiology
pub_type： 杂志文章,评审
doi：10.1007/s00395-016-0554-5
更新日期：2016-07-01 00:00:00
abstract：:Experimental evidence indicates that ischemic glycolysis improves myocardial tolerance to low flow ischemia and anoxia, and cellular membrane disruption signals and/or causes transition to irreversible ischemic injury. The objective of this study was to determine the impact of ischemic glycolysis on membrane integrity...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/s003950170013
更新日期：2001-11-01 00:00:00
abstract：:Urapidil (URA) is used to treat acute hypertension in patients with coronary artery disease, but the effect of URA on the performance of ischemic myocardium has not yet been investigated. The present study was intended to assess the function of ischemic myocardium following URA administration. In eight anesthetized (p...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/BF01907115
更新日期：1990-05-01 00:00:00
abstract：:The clinical use of positive inotropic agents has been associated with increased mortality, with proarrhythmia speculated to be a contributing factor. This study compares the arrhythmogenic potentials of six positive inotropic agents representing different mechanistic classes: the beta-adrenergic agonist dobutamine, t...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/s003950050181
更新日期：2000-06-01 00:00:00
abstract：:The effect of isoproterenol perfusion on cAMP levels and phosphorylase activity was investigated in the spontaneously hypertensive rat (SHR) and Kyoto Wistar normotensive control rat (WKY) heart. The basal force of contraction in physiological salt solution perfused hearts was comparable between SHR and WKY. However, ...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/BF01907217
更新日期：1983-11-01 00:00:00
abstract：:Transgenic and gene knockout rodent models are primordial to study pathophysiological processes in cardiovascular research. Over time, cardiac MRI has become a gold standard for in vivo evaluation of such models. Technical advances have led to the development of magnets with increasingly high field strength, allowing ...
journal_title：Basic research in cardiology
pub_type： 杂志文章,评审
doi：10.1007/s00395-016-0565-2
更新日期：2016-07-01 00:00:00
abstract：:A method is theoretically described to test the accuracy of various lead system of the ecg. The priniciple of this method consists in the following procedure. The heart position is changed maximally in a proband by varying the position of the body and by deep inspiration and exspiration. If the lead field is parallel,...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：
更新日期：1975-01-01 00:00:00
abstract：:A study of substrate selection in the isolated heart was made using 13C NMR isotopomer analysis, a method that unequivocally identifies relative substrate utilization. This technique has several advantages over conventional approaches used to study this problem. It detects the labeling of metabolic end-products presen...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/BF00788500
更新日期：1995-09-01 00:00:00
abstract：:Hearts preconditioned by brief ischemia are characterized by a reduced rate of cellular purine metabolite production during subsequent prolonged ischemia; the purpose of this study was to determine if transient exogenous adenosine pretreatment can mimic this phenomenon. The accumulation of interstitial fluid (ISF) pur...
journal_title：Basic research in cardiology
pub_type： 杂志文章
doi：10.1007/BF00796210
更新日期：1997-12-01 00:00:00
