Promotion of copper excretion from the isolated rat heart attenuates postischemic cardiac oxidative injury

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.

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.


1994 ◽  
Vol 266 (6) ◽  
pp. H2497-H2507 ◽  
Author(s):  
S. R. Powell ◽  
D. Hall ◽  
L. Aiuto ◽  
R. A. Wapnir ◽  
S. Teichberg ◽  
...  

We studied the cardiac protective qualities of zinc in the postischemic isolated rat heart. Hearts, perfused with Krebs-Henseleit buffer with or without zinc-bis-histidinate, were subjected to 20 min of "no-flow" normothermic global ischemia. Pre- and postischemic treatment with 0, 10, 20, or 30 microM zinc resulted in concentration-dependent enhancement of postischemic function as evidenced by decreased end-diastolic pressure (37 +/- 3, 25 +/- 5, 17 +/- 5, and 8 +/- 2 mmHg, respectively) and increased recovery of developed systolic pressure (41 +/- 6, 59 +/- 17, 76 +/- 18, and 87 +/- 16 mmHg, respectively) and maximum rate of rise in pressure (+dP/dtmax; 823 +/- 141, 1,413 +/- 396, 1,700 +/- 450, and 2,157 +/- 407 mmHg/s, respectively) as well as decreased lactate dehydrogenase efflux from the hearts (peak: 1,002%, 840%, 580%, and 440%, respectively). Only preischemic treatment resulted in an intermediate protective effect, whereas treatment starting at reperfusion worsened postischemic damage. In hearts perfused with zinc throughout the experiment, prolongation of the preischemic treatment interval further enhanced postischemic recovery. With the use of salicylate as a trap for .OH, it was determined that zinc virtually eliminated the early postischemic "burst" of this species normally observed in this preparation. Atomic absorption studies demonstrated that hearts treated with 30 microM zinc contained 27% less copper than control hearts by the end of the reperfusion period. In control hearts, electron microscopy revealed swollen mitochondria with marked loss of inner matrix density, whereas morphology of postischemic zinc-treated hearts was essentially normal. These studies indicate that zinc possesses cardiac cytoprotective qualities and support the concept that this metal can decrease .OH formation by affecting copper reactivity.


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.


1996 ◽  
Vol 271 (3) ◽  
pp. H876-H881 ◽  
Author(s):  
M. Tani ◽  
Y. Asakura ◽  
H. Hasegawa ◽  
K. Shinmura ◽  
Y. Ebihara ◽  
...  

The effect of varying the number of preconditioning (PC) episodes on the recovery of cardiac function and on the function of the sarcoplasmic reticulum (SR) was investigated to determine the correlation between the effect of PC and SR function. Isolated rat hearts were subjected to zero to three 5-min episodes of global ischemia with intermittent perfusion (PC0-PC3) followed by 25 min of ischemia (I) and 30 min of reperfusion. The left ventricular (LV) pressure and SR 45Ca2+ uptake in the absence or presence of ryanodine were then measured. The increase in LV end-diastolic pressure and the incidence and duration of ventricular tachyarrhythmias during reperfusion decreased. The recovery of LV developed pressure, LV dP/dtmax and dP/dtmin, increased as the number of episodes of PC increased. The rates of SR 45Ca2+ uptake after PC and after reperfusion were lower in PC3 than in PC0. Conversely, the rate of 45Ca2+ uptake after I did not differ between PC0 and PC3. The ryanodine-sensitive Ca2+ release increased after I, and additional increases were observed during reperfusion in PC0, whereas the release after I and reperfusion decreased progressively in PC3. These observations show that the beneficial effects of PC are associated with a decrease in ryanodine-sensitive SR Ca2+ release.


2002 ◽  
Vol 283 (4) ◽  
pp. H1307-H1313 ◽  
Author(s):  
Helen L. Maddock ◽  
Mihaela M. Mocanu ◽  
Derek M. Yellon

Ischemia-reperfusion induces both necrotic and apoptotic cell death. The ability of adenosine to attenuate reperfusion-induced injury (RI) and the role played by adenosine receptors are unclear. We therefore studied the role of the A3receptor (A3R) in ameliorating RI using the specific A3R agonist 1-[2-chloro-6-[[(3-iodophenyl)methyl]amino]-9 H-purin-9-yl]-1-deoxi- N-methyl-b-d-ribofuranuronamide (2-Cl-IB-MECA). Isolated rat hearts and cardiomyocytes were subjected to ischemia or simulated ischemia, followed by reperfusion/reoxygenation. The end points were percent infarction/risk zone and annexin-V (apoptosis) and/or propidium iodide positivity (necrosis), respectively. In isolated hearts, 2-Cl-IB-MECA significantly limited infarct size (44.2 ± 2.7% in control vs. 21.9 ± 2.4% at 1 nM and 35.8 ± 3.3% at 0.1 nM, P < 0.05). In isolated myocytes, apoptosis and necrosis were significantly reduced compared with controls (5.7 ± 2.6% vs. 17.1 ± 1.3% and 13.7 ± 2.0% vs. 23.1 ± 1.5%, respectively, P < 0.0001). In both models, the beneficial effects were abrogated using the A3R antagonist MRS-1191. The involvement of A2areceptor activation was also examined. This is the first study to demonstrate that A3R activation at reperfusion limits myocardial injury in the isolated rat heart and improves survival in isolated myocytes, possibly by antiapoptotic and antinecrotic mechanisms.


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.


2011 ◽  
Vol 301 (5) ◽  
pp. H2154-H2160 ◽  
Author(s):  
Munetaka Shibata ◽  
Daisuke Takeshita ◽  
Koji Obata ◽  
Shinichi Mitsuyama ◽  
Haruo Ito ◽  
...  

Impaired Ca2+ handling is one of the main characteristics in heart failure patients. Recently, we reported abnormal expressions of Ca2+-handling proteins in isoproterenol (ISO)-induced hypertrophied rat hearts. On the other hand, Na+/H+ exchanger (NHE)-1 inhibitor has been demonstrated to exert beneficial effects in ischemic-reperfusion injury and in the development of cardiac remodeling. The aims of the present study are to investigate the role of NHE-1 on Ca2+ handling and development of cardiac hypertrophy in ISO-infused rats. Male Wistar rats were randomly divided into vehicle [control (CTL)] and ISO groups without or with pretreatment with a selective NHE-1 inhibitor, BIIB-723. ISO infusion for 1 wk significantly increased the ratios of heart to body weight and left ventricle (LV) to body weight and collagen accumulation. All of these increases were antagonized by coadministration with BIIB-723. The ISO-induced significant increase in LV wall thickness was suppressed significantly ( P < 0.05) by BIIB-723. ISO-induced decreases in cardiac stroke volume and a total mechanical energy per beat index, systolic pressure-volume area at midrange LV volume, were normalized by BIIB-723. The markedly higher expression of NHE-1 protein in the ISO group than that in CTL group was suppressed ( P < 0.05) by BIIB-723. Surprisingly, ISO induced downregulation of the important Ca2+-handling protein sarcoplasmic reticulum Ca2+-ATPase 2a, the expression of which was also normalized by BIIB-723 without changes in phosphorylated phospholamban (PLB)/PLB expression. We conclude that NHE-1 contributes to ISO-induced abnormal Ca2+ handling associated with cardiac hypertrophy. Inhibition of NHE-1 ameliorates cardiac Ca2+-handling impairment and prevents the development of cardiac dysfunction in ISO-infused rats.


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Jonathas F Almeida ◽  
Robson A Santos

Alamandine, a biologically active peptide of the renin-angiotensin system (RAS), was recently described and characterized. Further it has been shown to present effects similar to those elicited by Ang-(1-7). It has been described that Ang-(1-7) decreases the incidence and duration of ischemia-reperfusion arrhythmias and improved the post-ischemic function in isolated perfused rat hearts. In this study we aimed to evaluate the effects of Alamandine in isolated rat hearts subjected to myocardial infarction (MI). Wistar rats weighing between 250-300g were euthanized and their hearts were placed on Langendorff apparatus to evaluate the cardiac parameters. Hearts were submitted to 30min of stabilization, 30min of partial ischemia by occlusion of the left descending coronary artery and 30min of reperfusion. Drugs (alamandine 22pM, d-pro7-ang-(1-7) 220pM) were added to the perfusion setting from the beginning of the experiment until the end. 2,3,5-trypheniltetrazolium chloride were used to evaluate the extension of infarcted area. In control hearts (CON), there was a decrease on the left ventricular systolic pressure (LVSP) on ischemic period (54,6 ± 6,9mmHg) compared to the baseline period (84,6 ± 11,6mmHg). Alamandine (ALA) attenuated that decrease in the ischemic period (66,9 ± 7,9mmHg) vs (82,3 ± 8,9mmHg). Further, ischemia led to a decrease in the left ventricular developed pressure (dLVP), dP/dt maximum and minimum when compared to baseline values. ALA, once more, kept the ischemic parameters of dLVP and dP/dt max and min (58,9 ± 8mmHg; 1629 ± 202,2mmHg/s; 1101 ± 130mmHg/s, respectively) similar to those of baseline period (68,9 ± 8,92; 1682 ± 248,8; 1179 ± 118,6 mmHg, respectively). Ischemia/reperfusion induced an arrhythmia severity index (ASI) in control hearts (4,9 ± 1,26) higher than in hearts treated with ALA (1,10 ± 0,58). ALA also reduced infarcted area (19,64 ± 2,61%) compared with CON (33,85 ± 4,55%). All those effects were blocked by D-PRO7-Ang-(1-7). In conclusion, our data shown that Alamandine exert cardioprotective effects in post-ischemic function in isolated rat hearts by preventing LVSP, dLVP , dP/dt max and min decrease. Furthermore it reduced the infarcted area and I/R arrhythmias, apparently involving MrgD receptor participation.


1998 ◽  
Vol 274 (3) ◽  
pp. H846-H852 ◽  
Author(s):  
Maurits A. Jansen ◽  
Cees J. A. Van Echteld ◽  
Tom J. C. Ruigrok

Ca2+paradox damage has been suggested to be determined by Na+ entry during Ca2+ depletion and exchange of Na+ for Ca2+ during Ca2+ repletion. With the use of23Na nuclear magnetic resonance, we previously observed a Ca2+ paradox without a prior Na+ increase. We have now demonstrated a Na+ increase during Ca2+ and Mg2+ depletion without the occurrence of the Ca2+ paradox during Ca2+ repletion. Isolated rat hearts were perfused for 20 min with a Ca2+-free or a Ca2+- and Mg2+-free (Ca2+/Mg2+-free) solution under hypothermic conditions (20 and 25°C). Intracellular Na+ concentration ([Na+]i) increased from 11.9 ± 1.2 to 26.9 ± 5.8 mM ( P < 0.001) during Ca2+/Mg2+-free perfusion at 20°C, whereas no significant change in [Na+]ioccurred during 20 min of Ca2+-free perfusion at 20°C. In addition, we confirmed that [Na+]idid not change significantly during 20 min of normothermic Ca2+-free perfusion. Creatine kinase release during normothermic Ca2+ repletion in the 20°C groups was ∼10% and in the 25°C groups 75% of the release in the normothermia group. Recovery of rate-pressure product was ∼50% in the 20°C groups versus 0% in the normothermia group. In conclusion, hypothermic Ca2+/Mg2+-free perfusion results in a significant increase of [Na+]i, which does not contribute to the extent of the Ca2+ paradox on normothermic Ca2+ repletion.


2009 ◽  
Vol 297 (5) ◽  
pp. H1736-H1743 ◽  
Author(s):  
Chikako Nakajima-Takenaka ◽  
Guo-Xing Zhang ◽  
Koji Obata ◽  
Kiyoe Tohne ◽  
Hiroko Matsuyoshi ◽  
...  

We investigated left ventricular (LV) mechanical work and energetics in the cross-circulated (blood-perfused) isoproterenol [Iso 1.2 mg·kg−1·day−1 for 3 days (Iso3) or 7 days (Iso7)]-induced hypertrophied rat heart preparation under isovolumic contraction-relaxation. We evaluated pressure-time curves per beat, end-systolic pressure-volume and end-diastolic pressure-volume relations, and myocardial O2 consumption per beat (V̇o2)-systolic pressure-volume area (PVA; a total mechanical energy per beat) linear relations at 240 beats/min, because Iso-induced hypertrophied hearts failed to completely relax at 300 beats/min. The LV relaxation rate at 240 beats/min in Iso-induced hypertrophied hearts was significantly slower than that in control hearts [saline 24 μl/day for 3 and 7 days (Sa)] with unchanged contraction rate. The V̇o2-intercepts (composed of basal metabolism and Ca2+ cycling energy consumption in excitation-contraction coupling) of V̇o2-PVA linear relations were unchanged associated with their unchanged slopes in Sa, Iso3, and Iso7 groups. The oxygen costs of LV contractility were also unchanged in all three groups. The amounts of expression of sarcoplasmic reticulum Ca2+-ATPase, phospholamban (PLB), phosphorylated-Ser16 PLB, phospholemman, and Na+-K+-ATPase are significantly decreased in Iso3 and Iso7 groups, although the amount of expression of NCX1 is unchanged in all three groups. Furthermore, the marked collagen production (types I and III) was observed in Iso3 and Iso7 groups. These results suggested the possibility that lowering the heart rate was beneficial to improve mechanical work and energetics in isoproterenol-induced hypertrophied rat hearts, although LV relaxation rate was slower than in normal hearts.


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