scholarly journals Aspirate from stented aortocoronary saphenous vein grafts reduces coronary flow and left ventricular pressure in an isolated perfused rat hearts

2015 ◽  
Vol 29 (S1) ◽  
Author(s):  
Petra Kleinbongard ◽  
Helmut Lieder ◽  
Philipp Kahlert ◽  
Gerd Heusch
Keyword(s):  
Saphenous Vein ◽  
Coronary Flow ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Vein Grafts ◽  
Saphenous Vein Grafts ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Isolated Perfused Rat Hearts

Thermodynamic limitation for Ca2+ handling contributes to decreased contractile reserve in rat hearts

1998 ◽  
Vol 275 (6) ◽  
pp. H2064-H2071 ◽  
Author(s):  
Rong Tian ◽  
Jessica M. Halow ◽  
Markus Meyer ◽  
Wolfgang H. Dillmann ◽  
Vincent M. Figueredo ◽  
...  
Keyword(s):  
Atp Hydrolysis ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Contractile Reserve ◽  
Rat Hearts ◽  
Intracellular Ca ◽  
Perfused Rat Hearts ◽  
Thermodynamic Driving Force ◽  
Developed Pressure ◽  
Isolated Perfused Rat Hearts

The free energy release from ATP hydrolysis (‖ΔG∼p‖) is decreased by inhibiting the creatine kinase (CK) reaction, which may limit the thermodynamic driving force for the sarcoplasmic reticulum (SR) Ca2+ pumps and thereby cause a decrease in contractile reserve. To determine whether a decrease in ‖ΔG∼p‖ results in decreased contractile reserve by impairing Ca2+ handling, we measured left ventricular pressure and cytosolic Ca2+concentration ([Ca2+]c; by indo 1 fluorescence) in isolated perfused rat hearts, with >95% inhibition of CK with 90 μmol iodoacetamide. Iodoacetamide did not directly alter SR Ca2+-ATPase activity, baseline left ventricular developed pressure, or baseline [Ca2+]c. When perfusate Ca2+ concentration was increased from 1.2 to 3.3 mM, LV developed pressure increased from 67 ± 6 to 119 ± 8 mmHg in control hearts ( P < 0.05) but did not significantly increase in CK-inhibited hearts. Similarly, the amplitude of the [Ca2+]ctransient increased from 548 ± 54 to 852 ± 140 nM in control hearts ( P < 0.05) but did not significantly increase in CK-inhibited hearts. We conclude that decreased ‖ΔG∼p‖ limits intracellular Ca2+ handling and thereby limits contractile reserve.

Contribution of extravascular compression to reduction of maximal coronary blood flow

1992 ◽  
Vol 262 (1) ◽  
pp. H68-H77
Author(s):  
F. L. Abel ◽  
R. R. Zhao ◽  
R. F. Bond
Keyword(s):  
Blood Flow ◽  
Coronary Blood Flow ◽  
Coronary Flow ◽  
Perfusion Pressure ◽  
Left Ventricular Pressure ◽  
Coronary Perfusion Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Coronary Perfusion ◽  
Storage Site

Effects of ventricular compression on maximally dilated left circumflex coronary blood flow were investigated in seven mongrel dogs under pentobarbital anesthesia. The left circumflex artery was perfused with the animals' own blood at a constant pressure (63 mmHg) while left ventricular pressure was experimentally altered. Adenosine was infused to produce maximal vasodilation, verified by the hyperemic response to coronary occlusion. Alterations of peak left ventricular pressure from 50 to 250 mmHg resulted in a linear decrease in total circumflex flow of 1.10 ml.min-1 x 100 g heart wt-1 for each 10 mmHg of peak ventricular to coronary perfusion pressure gradient; a 2.6% decrease from control levels. Similar slopes were obtained for systolic and diastolic flows as for total mean flow, implying equal compressive forces in systole as in diastole. Increases in left ventricular end-diastolic pressure accounted for 29% of the flow changes associated with an increase in peak ventricular pressure. Doubling circumferential wall tension had a minimal effect on total circumflex flow. When the slopes were extrapolated to zero, assuming linearity, a peak left ventricular pressure of 385 mmHg greater than coronary perfusion pressure would be required to reduce coronary flow to zero. The experiments were repeated in five additional animals but at different perfusion pressures from 40 to 160 mmHg. Higher perfusion pressures gave similar results but with even less effect of ventricular pressure on coronary flow or coronary conductance. These results argue for an active storage site for systolic arterial flow in the dilated coronary system.

Nature of [Ca2+]i transients during ventricular fibrillation and quinidine treatment in perfused rat hearts

1994 ◽  
Vol 266 (4) ◽  
pp. H1473-H1484
Author(s):  
S. Kojima ◽  
J. Wikman-Coffelt ◽  
S. T. Wu ◽  
W. W. Parmley
Keyword(s):  
Ventricular Fibrillation ◽  
Control Level ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Acetoxymethyl Ester ◽  
Ecg Signals ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Electrocardiogram Ecg ◽  
The Relationship

We studied intracellular Ca2+ concentration ([Ca2+]i) and the electrocardiographic signals during pacing-induced ventricular fibrillation (VF) and quinidine treatment (0.4 mg/min) using surface fluorometry in indo 1-acetoxymethyl ester (AM)-loaded perfused rat hearts. [Ca2+]i was evaluated as the indo 1 fluorescence ratio (F400/F510) and expressed as a percentage of the control amplitude of F400/F510 transients. F400/F510 increased to approximately 250% during 2- (n = 14) or 20-min (n = 9) VF. Quinidine significantly decreased F400/F510 by 60% after 2-min VF; however, this effect was blunted after 20-min VF. After 2-min VF, F400/F510 and left ventricular pressure recovered almost to the control level. However, recovery of F400/F510 and ventricular function was poor after 20-min VF. The relationship between [Ca2+]i and the electrocardiogram (ECG) during VF was evaluated by power spectrum analysis of F400/F510 and ECG signals. During VF (25 +/- 3 Hz) with high irregularity, there were no clear [Ca2+]i transients (n = 110). When the cardiac rhythm (22 +/- 3 Hz) was regular, including ventricular tachycardia, there were recognizable [Ca2+]i signals with dominant frequencies that were the same (n = 2), one-half (n = 12), or one-third (n = 1) of the ECG frequencies. The highest frequency of the [Ca2+]i transients was 19 Hz. During quinidine treatment, the VF rate decreased significantly, and clear [Ca2+]i transients were noted in all records responding to every one or two ECG signals. The conclusions were the following: 1) [Ca2+]i responds to electrical signals rapidly (up to 19 Hz) during VF. This fast [Ca2+]i response is a probable cause of high [Ca2+]i during VF. 2) Quinidine decreased [Ca2+]i after 2-min VF possibly in part by slowing the VF and [Ca2+]i transients rates. 3) 20-min VF caused [Ca2+]i overload and poor functional recovery after defibrillation.

Anesthetic Preconditioning

2003 ◽  
Vol 99 (2) ◽  
pp. 385-391 ◽  
Author(s):  
Leo G. Kevin ◽  
Peter Katz ◽  
Amadou K. S. Camara ◽  
Enis Novalija ◽  
Matthias L. Riess ◽  
...  
Keyword(s):  
Coronary Flow ◽  
Vascular Dysfunction ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Ischemic Time ◽  
Langendorff Preparation ◽  
Anesthetic Preconditioning ◽  
Structural Variables ◽  
Serious Injury

Background Anesthetic preconditioning (APC) is protective for several aspects of cardiac function and structure, including left ventricular pressure, coronary flow, and infarction. APC may be protective, however, only if the duration of ischemia is within a certain, as yet undefined range. Brief ischemia causes minimal injury, and APC would be expected to provide little benefit. Conversely, very prolonged ischemia would ultimately cause serious injury with or without APC. Previous investigations used a constant ischemic time as the independent variable to assess ischemia-induced changes in dependent functional and structural variables. The purpose of the study was to define the critical limits of efficacy of APC by varying ischemic time. Methods Guinea pig hearts (Langendorff preparation; n = 96) underwent pretreatment with sevoflurane (APC) or no treatment (control), before global ischemia and 120 min reperfusion. Ischemia durations were 20, 25, 30, 35, 40, and 45 min. Results At 120 min reperfusion, developed (systolic-diastolic) left ventricular pressure was increased by APC compared with control for ischemia durations of 25-40 min. Infarction was decreased by APC for ischemia durations of 25-40 min, but not 20 or 45 min. APC improved coronary flow and vasodilator responses for all ischemia durations longer than 25 min, and decreased ventricular fibrillation on reperfusion for ischemia durations longer than 30 min. Conclusions Although APC protects against vascular dysfunction and dysrhythmias after prolonged ischemia, protection against contractile dysfunction and infarction in this model is restricted to a range of ischemia durations of 25-40 min. These results suggest that APC may be effective in a subset of patients who have cardiac ischemia of intermediate duration.

Inhibition of nitric oxide synthesis does not affect ischemic preconditioning in isolated perfused rat hearts

1995 ◽  
Vol 268 (1) ◽  
pp. H242-H249 ◽  
Author(s):  
E. O. Weselcouch ◽  
A. J. Baird ◽  
P. Sleph ◽  
G. J. Grover
Keyword(s):  
Nitric Oxide ◽  
Ischemic Preconditioning ◽  
Coronary Flow ◽  
Constant Pressure ◽  
Contractile Function ◽  
No Synthase ◽  
Constant Flow ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Isolated Perfused Rat Hearts

Endothelium-derived nitric oxide (NO) has recently been reported to be a mediator of ischemic preconditioning in dog hearts. The aim of the present study was to determine the role of NO in ischemic preconditioning in isolated perfused rat hearts. Rat hearts were perfused at either constant pressure (80 mmHg) or constant flow. After aerobic perfusion (37 degrees C) for 10 min, hearts were treated with N omega-nitro-L-arginine methyl ester (L-NAME; 30 microM), which is an inhibitor of NO synthase, or vehicle. Ten minutes later, the hearts were preconditioned (4 episodes of 5 min of global ischemia and 5 min of reperfusion) or perfused normally before a 30-min global ischemic period. All hearts were reperfused for 30 min. Coronary flow or perfusion pressure plus heart rate and contractile function were measured continuously. Hearts perfused at constant pressure and treated with 30 microM L-NAME, a concentration that effectively inhibits endogenous NO synthesis, exhibited decreased coronary flow after 10 min, and flow remained decreased throughout the experiment. Ischemic preconditioning before 30 min of global ischemia resulted in a doubling of contractile function and a reduction of lactate dehydrogenase release at the end of the 30-min reperfusion period compared with nonpreconditioned hearts. The protective effect of preconditioning was not different in L-NAME-treated hearts. In addition, inhibition of NO synthase had no effect on the severity of ischemia in nonpreconditioned hearts. Similar results were obtained in preconditioned hearts that were perfused at constant flow, indicating that the flow reductions caused by L-NAME did not influence the results.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of diazoxide on flavoprotein oxidation and reactive oxygen species generation during ischemia-reperfusion: a study on Langendorff-perfused rat hearts using optic fibers

2008 ◽  
Vol 294 (5) ◽  
pp. H2088-H2097 ◽  
Author(s):  
Philippe Pasdois ◽  
Bertrand Beauvoit ◽  
Liliane Tariosse ◽  
Béatrice Vinassa ◽  
Simone Bonoron-Adèle ◽  
...  
Keyword(s):  
Ischemia Reperfusion ◽  
Reactive Oxygen Species Generation ◽  
Left Ventricular ◽  
Rate Pressure Product ◽  
Control Group ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Optic Fibers ◽  
The One ◽  
Isolated Perfused Rat Hearts

This study analyzed the oxidant generation during ischemia-reperfusion protocols of Langendorff-perfused rat hearts, preconditioned with a mitochondrial ATP-sensitive potassium channel (mitoKATP) opener (i.e., diazoxide). The autofluorescence of mitochondrial flavoproteins, and that of the total NAD(P)H pool on the one hand and the fluorescence of dyes sensitive to H2O2 or O2•− [i.e., the dihydrodichlorofluoroscein (H2DCF) and dihydroethidine (DHE), respectively] on the other, were noninvasively measured at the surface of the left ventricular wall by means of optic fibers. Isolated perfused rat hearts were subjected to an ischemia-reperfusion protocol. Opening mitoKATP with diazoxide (100 μM) 1) improved the recovery of the rate-pressure product after reperfusion (72 ± 2 vs. 16.8 ± 2.5% of baseline value in control group, P < 0.01), and 2) attenuated the oxidant generation during both ischemic (−46 ± 5% H2DCF oxidation and −40 ± 3% DHE oxidation vs. control group, P < 0.01) and reperfusion (−26 ± 2% H2DCF oxidation and −23 ± 2% DHE oxidation vs. control group, P < 0.01) periods. All of these effects were abolished by coperfusion of 5-hydroxydecanoic acid (500 μM), a mitoKATP blocker. During the preconditioning phase, diazoxide induced a transient, reversible, and 5-hydroxydecanoic acid-sensitive flavoprotein and H2DCF (but not DHE) oxidation. In conclusion, the diazoxide-mediated cardioprotection is supported by a moderate H2O2 production during the preconditioning phase and a strong decrease in oxidant generation during the subsequent ischemic and reperfusion phases.

scholarly journals Coronary flow and left ventricular pressure during diastole in the anaesthetized dog

1992 ◽  
Vol 77 (2) ◽  
pp. 397-400 ◽  
Author(s):  
D Gattullo ◽  
RJ Linden ◽  
G Losano ◽  
P Pagliaro ◽  
N Westerhof
Keyword(s):  
Coronary Flow ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Anaesthetized Dog

scholarly journals Rutin trihydrate attenuated cisplatin- induced cardiac toxicity in isolated perfused rat’s hearts

2020 ◽  
Author(s):  
Ishfaq Bukhari ◽  
Osama Yousif Mohamed ◽  
Rahmathunnisa Lateef ◽  
Sabiha Fatima ◽  
Fahim Vohra ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Left Ventricular ◽  
Dependent Manner ◽  
Protective Effects ◽  
Time Index ◽  
Pressure Time ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Dose Dependent ◽  
Isolated Perfused Rat Hearts

Abstract Background The present study aims to investigate the protective effect of rutin against cisplatin induced toxic effects on the mechanical performance of the myocardium, histopathology, and oxidative stress in isolated perfused rat hearts. Methods Cardiotoxicity of cisplatin was assessed at three dosage levels (1, 7, and 14 mg/l) in the isolated perfused rat hearts. The toxic effect of cisplarin was assessed on left ventricular pressure (LVP), heart rate (HR), dp/dt(max), dp/dt (min), perfusion pressure, pressure-time index, contractility index and duration of diastole. Measurements were carried out one minute before perfusion of cisplatin and 60 minutes after perfusion. Results Cisplatin reduced significantly (p < 0.05) in a dose-dependent manner LVP, dp/dt(max), dp/dt(min) and pressure- time index. Perfusion of rutin trihydrate (1 µM/l), 10 minutes before administration of cisplatin and throughout the experiment significantly (p < 0.05) attenuated the detrimental effects of cisplatin on cardiac parameters. Cisplatin caused degeneration and necrosis of cardiac muscle cells, while rutin reduced these changes and restored normal heart histology. Moreover, cisplatin reduced the myocardium concentration of reduced glutathione and increased the level of malondialdehyde, whereas rutin almost reversed these changes. Conclusion Cisplatin-induced dose-dependent impairment of several parameters of cardiac function and produced histopathological alterations in isolated rat hearts. These harmful effects of cisplatin were ameliorated by rutin trihydrate. These findings suggest the potential protective effects of rutin trihydrate against cisplatin-induced cardiotoxicity.

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