Sodium alterations in isolated rat heart during cardioplegic arrest

1996 ◽  
Vol 81 (6) ◽  
pp. 2696-2702 ◽  
Author(s):  
V. D. Schepkin ◽  
I. O. Choy ◽  
T. F. Budinger

Schepkin, V. D., I. O. Choy, and T. F. Budinger. Sodium alterations in isolated rat heart during cardioplegic arrest. J. Appl. Physiol. 81(6): 2696–2702, 1996.—Triple-quantum-filtered (TQF) Na nuclear magnetic resonance (NMR) without chemical shift reagent is used to investigate Na derangement in isolated crystalloid perfused rat hearts during St. Thomas cardioplegic (CP) arrest. The extracellular Na contribution to the NMR TQF signal of a rat heart is found to be 73 ± 5%, as determined by wash-out experiments at different moments of ischemia and reperfusion. With the use of this contribution factor, the estimated intracellular Na ([Na+]i) TQF signal is 222 ± 13% of preischemic level after 40 min of CP arrest and 30 min of reperfusion, and the heart rate pressure product recovery is 71 ± 8%. These parameters are significantly better than for stop-flow ischemia: 340 ± 20% and 6 ± 3%, respectively. At 37°C, the initial delay of 15 min in [Na+]igrowth occurs during CP arrest along with reduced growth later (∼4.0%/min) in comparison with stop-flow ischemia (∼6.7%/min). The hypothermia (21°C, 40 min) for the stop-flow ischemia and CP dramatically decreases the [Na+]igain with the highest heart recovery for CP (∼100%). These studies confirm the enhanced sensitivity of TQF NMR to [Na+]iand demonstrate the potential of NMR without chemical shift reagent to monitor [Na+]iderangements.

1992 ◽  
Vol 263 (3) ◽  
pp. H887-H894 ◽  
Author(s):  
G. K. Asimakis ◽  
K. Inners-McBride ◽  
G. Medellin ◽  
V. R. Conti

The hypothesis that brief ischemia (preconditioning) protects the isolated heart from prolonged global ischemia was tested. Isovolumic rat hearts were preconditioned with either 5 min of ischemia followed by 5 min of perfusion (P1) or two 5-min episodes of ischemia separated by 5 min of perfusion (P2). Control hearts received no preconditioning. All hearts received 40 min of sustained ischemia and 30 min of reperfusion. Preconditioning (P1 or P2) significantly (P less than 0.0005) improved recovery of the rate-pressure product; percentage recoveries were 17.8 +/- 3.2 (n = 14), 59.9 +/- 5.5 (n = 6), and 46.4 +/- 4.7 (n = 8) for control, P1, and P2, respectively. Improved functional recovery of preconditioned hearts was associated with reduced end-diastolic pressure and improved myocardial perfusion. During the 40-min ischemic period, myocardial pH decreased from approximately 7.4 to 6.3 +/- 0.1 (n = 7) in the control hearts and to 6.7 +/- 0.1 (n = 7) in the preconditioned hearts (P less than 0.01). Also during the 40-min ischemic period, myocardial lactate (expressed as nmol/mg protein) increased to 146 +/- 11 (n = 7) and 101 +/- 12 (n = 8) in control and preconditioned hearts, respectively (P less than 0.02). The results demonstrate that a brief episode of ischemia can protect the isolated rat heart from a prolonged period of ischemia. This protection is associated with decreased tissue acidosis and anaerobic glycolysis during the sustained ischemic period.


2006 ◽  
Vol 8 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Autumn M. Schumacher ◽  
Joseph P. Zbilut ◽  
Charles L. Webber ◽  
Dorie W. Schwertz ◽  
Mariann R. Piano

Cardiac variability can be assessed from two perspectives: beat-to-beat performance and continuous performance during the cardiac cycle. Linear analysis techniques assess cardiac variability by measuring the physical attributes of a signal, whereas nonlinear techniques evaluate signal dynamics. This study sought to determine if recurrence quantification analysis (RQA), a nonlinear technique, could detect pharmacologically induced autonomic changes in the continuous left ventricular pressure (LVP) and electrographic (EC) signals from an isolated rat heart—a model that theoretically contains no inherent variability. LVP and EC signal data were acquired simultaneously during Langendorff perfusion of isolated rat hearts before and after the addition of acetylcholine (n = 11), norepinephrine (n = 12), or no drug (n = 12). Two-minute segments of the continuous LVP and EC signal data were analyzed by RQA. Findings showed that%recurrence,%determinism, entropy, maxline, and trend from the continuous LVP signal significantly increased in the presence of both acetylcholine and norepinephrine, although systolic LVP significantly increased only with norepinephrine. In the continuous EC signal, the RQA trend variable significantly increased in the presence of norepinephrine. These results suggest that when either the sympathetic or parasympathetic division of the autonomic nervous system overwhelms the other, the dynamics underlying cardiac variability become stationary. This study also shows that information concerning inherent variability in the isolated rat heart can be gained via RQA of the continuous cardiac signal. Although speculative, RQA may be a tool for detecting alterations in cardiac variability and evaluating signal dynamics as a nonlinear indicator of cardiac pathology.


2010 ◽  
Vol 113 (6) ◽  
pp. 1320-1325 ◽  
Author(s):  
Ying Chen ◽  
Yun Xia ◽  
Le Liu ◽  
Tong Shi ◽  
Kejian Shi ◽  
...  

Background The concentration-response and time-response relationships of lipid emulsions used to reverse bupivacaine-induced asystole are poorly defined. Methods Concentration response across a range of lipid concentrations (0-16%) to reverse bupivacaine-induced asystole were observed using isolated rat heart Langendorff preparation. Cardiac function parameters were recorded during infusion. Concentrations of bupivacaine in myocardial tissue were measured by liquid chromatography and tandem mass spectrometry at the end of the experiment. Results Although all lipid-treated hearts recovered (cardiac recovery was defined as a rate-pressure product more than 10% baseline), no nonlipid-treated hearts (control group) did so. The ratio of the maximum rate pressure product during recovery to baseline value demonstrated a concentration-dependent relationship among lipid groups, with 0.25, 0.5, 1, 2, 4, 8, and 16%. Mean ± SD values for each corresponding group were 22 ± 4, 24 ± 5, 29 ± 6, 52 ± 11, 73 ± 18, 119 ± 22, and 112 ± 10%, respectively (n = 6, P < 0.01). Rate-pressure product in lipid groups with 4-16% concentrations was lower at 15-40 min than at 1 min, showing a decreasing tendency during recovery phase (P < 0.01). The concentration of myocardial bupivacaine in all lipid-treated groups was significantly lower than in the control group (P < 0.01). It was also lower in lipid groups with 2-16% concentrations than in those with concentrations at 0.25-1% (P < 0.05), with the 16% group lower than groups with 2-8% concentrations (P < 0.001). Conclusion Lipid application in bupivacaine-induced asystole displays a concentration-dependent and time-response relationship in isolated rat hearts.


2016 ◽  
Vol 20 (4) ◽  
pp. 88
Author(s):  
R. A. Knyazev ◽  
N. V. Trifonova ◽  
A. R. Kolpakov ◽  
L. M. Polyakov

<p><strong>Aim.</strong> Chemotherapy is one of the main methods of treating malformations. However, this technique causes a great deal of side effects, among which are complications related to cardiac toxicity. Development of new anticancer drugs is directly related to a decrease in the general toxic effect on the organism and the cardiovascular system in particular. The aim of the study was to investigate the capability of apolipoprotein A-1 together with an anticancer drug, actinomycin D, to induce functional disturbances in the performance of an isolated rat heart and to compare the effect with that of pure actinomycin D. <br /><strong>Methods.</strong> For experiments use was made of Wistar male rats weighing 220-250 g. A modified Krebbs-Henseleit buffer saturated with carbogene (95 % O2 and 5 % CO2, solution temperature 37.5 °C) was used as perfusate. Experiments were conducted on isolated rat hearts. The isolated rat hearts were perfused retrogradely by a standard procedure, with isovolumic pressure registered in the left ventricle. Apolipoprotein A-I was isolated of human high-density lipoprotein by delipidating followed by separation of the proteins mix by means of column chromatography. In the experiment, apolipoprotein A-I- was mixed with actinomycin D, with concentration of the anticancer drug in the complex being 0.1 µg/ml.<br /><strong>Results</strong>. Actinomycin D with concentration 1 µg/ml aggravates the functional indicators of the heart and enhances energy load on the myocardium. Decreasing the concentration of cytostatic down to 0.1 µg/ml of perfusate brings the indicators to the baseline values. Apolipoprotein A-I combined with actinomycin D offsets the changes introduced by the cytostatic without a carrier. The complex improves hemodynamics, which can be interpreted by the presence of a protein component.<br /><strong>Conclusion.</strong> An isolated rat heart model shows that apolipoprotein A-I in combination with 0.1 µg/ml actinomycin D does not cause cardio toxicity. The complex improves myocardial efficiency through the use of the protein component as a carrier of the anticancer drug.</p><p>Received 15 November 2016. Accepted 30 November 2016.</p><p><strong>Funding:</strong> The research was supported by the federal budget project implemented by Research Institute of Biochemistry, Reg. R-085.<br /><strong>Conflict of interest:</strong> The authors declare no conflict of interest.<br /><strong>Author contributions</strong><br />Conceptualization and study design: Kolpakov AR. <br />Сбор и обработка материала: Knyazev R.A., Trifonova N.V.<br />Statistical data processing: Knyazev R.A.<br />Article writing: Knyazev R.A.<br />Review &amp; editing: Polyakov L.M.</p>


1999 ◽  
Vol 277 (3) ◽  
pp. H956-H962 ◽  
Author(s):  
Saul R. Powell ◽  
Ellen M. Gurzenda ◽  
Mark A. Wingertzahn ◽  
Raul A. Wapnir

This study examined the role of Cu as a mediator of cardiac postischemic oxidative injury. Isolated rat hearts were subjected to 20 min of normothermic global ischemia, followed by 30 min of reperfusion; after 20 min of preischemic loading with Krebs-Henseleit buffer ± 20 or 30 μM zinc-bis-histidinate (Zn-His2), 0.5 mM deferoxamine (DEF) or 42 μM neocuproine (NEO). Postischemic developed systolic pressure and rate-pressure product were highest and postischemic end-diastolic pressure was lowest in hearts treated with 20 or 30 μM Zn-His2 and 0.5 mM DEF. Cu efflux was significantly increased by 225 and 290% (end of preischemic loading), and 325 and 375% (immediate postischemic period) of control basal rates in hearts treated with 30 μM Zn-His2 and 0.5 mM DEF, respectively. NEO did not effect any of these parameters. By the end of ischemia, protein carbonyls were lowest in Zn-His2-treated hearts and highest in DEF-treated hearts when compared with control hearts. The results of this study suggest that removal of redox-active Cu before ischemia has beneficial effects, indicating a mediatory role in postischemic cardiac oxidative injury.


1998 ◽  
Vol 275 (6) ◽  
pp. H2266-H2271 ◽  
Author(s):  
Shuji Kawamura ◽  
Ken-Ichi Yoshida ◽  
Toshiro Miura ◽  
Yoichi Mizukami ◽  
Masunori Matsuzaki

Protein kinase C (PKC) plays an important role in mediating ischemic preconditioning (PC). However, the relationship between PKC isoforms and PC is still uncertain. We analyzed subcellular localization of PKC isoforms by Western blot analysis in isolated rat heart and demonstrate that PKC-α, -δ, and -ε were translocated to the membrane fraction associated with the improvement of cardiac function. Translocation of PKC-δ and -ε persisted after a 30-min period following PC, but the translocation of PKC-α was transient. Under low Ca2+ perfusion (0.2 mmol/l), PC improved the cardiac function associated with the translocation of PKC-δ. Chelerythrine (1.0 μmol/l) suppressed the translocation of all PKC isoforms associated with the loss of improvement of the cardiac function. On the other hand, bisindolylmaleimide (0.1 μmol/l) did not inhibit the improvement of cardiac function induced by PC, which was associated with the translocation of PKC-ε. These results indicate that the effect of PC on cardiac function is mediated by the translocation of either PKC-δ or -ε independently in rat hearts.


1992 ◽  
Vol 24 ◽  
pp. 160 ◽  
Author(s):  
Daniel Ogorek ◽  
Edith Hochhauser ◽  
Eran Geller ◽  
Bernardo Vidne ◽  
Pinchas Halpern ◽  
...  

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