Sublytic complement attack reduces infarct size in rabbit isolated hearts: evidence for C5a-mediated cardioprotection

Background The influence of anesthetic agents on the infarction process in the ischemic myocardium is unclear. This study evaluated the effects of three intravenous and three inhalational anesthetic agents on myocardial infarction within a quantified ischemic risk zone in rabbit hearts subjected to a standardized regional ischemia-reperfusion insult. Methods Both in vitro and in situ rabbit models were used to investigate the effects of anesthetic agents on infarct size. In all rabbits the heart was exposed and a coronary artery surrounded with a suture to form a snare for subsequent occlusion. In in situ preparations, both intravenous and inhalational agents were tested, whereas only the latter were used in isolated hearts. Infarct size was determined by triphenyltetrazolium chloride staining. To determine whether an adenosine-mediated protective mechanism was involved, 8-(p-sulfophenyl)theophylline, an adenosine receptor blocker, was added to halothane-treated isolated hearts. Adenosine concentration in the coronary effluent was also measured in isolated hearts exposed to halothane. In other protocols, chelerythrine, a highly selective protein kinase C inhibitor, was administered to both halothane-treated and untreated isolated hearts. Results Infarcts in the three in situ groups anesthetized with halothane, enflurane, and isoflurane were about one half as large as infarcts in rabbits that underwent anesthesia with pentobarbital, ketamine-xylazine, or propofol. Volatile anesthetics also protected isolated hearts by a similar amount. Both adenosine receptor blockade and chelerythrine abolished cardioprotection from halothane in isolated hearts. Halothane treatment did not increase adenosine release. Conclusions The volatile anesthetics tested protected the ischemic rabbit heart from infarction, in contrast to the three intravenous agents tested. Protection was independent of the hypotensive effect of the inhalational agents because halothane also protected isolated hearts, in which changing vascular tone is not an issue and coronary perfusion pressure is constant. Cardioprotection by volatile anesthetics depended on both adenosine receptors and protein kinase C, and thus is similar to the mechanism of protection seen with ischemic preconditioning.

Download Full-text

Comparison of two methods to automatically quantify infarct size in rat isolated hearts following global ischemia and reperfusion (1154.6)

The FASEB Journal ◽

10.1096/fasebj.28.1_supplement.1154.6 ◽

2014 ◽

Vol 28 (S1) ◽

Author(s):

Matthias Riess ◽

Sushrut Shidham ◽

Raha Nabbi ◽

Wolfgang Gaggl ◽

Alexandra Lerch‐Gaggl

Keyword(s):

Infarct Size ◽

Global Ischemia ◽

Ischemia And Reperfusion ◽

Isolated Hearts

Download Full-text

Blocking Na+/H+ exchange reduces [Na+]i and [Ca2+]i load after ischemia and improves function in intact hearts

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.2001.281.6.h2398 ◽

2001 ◽

Vol 281 (6) ◽

pp. H2398-H2409 ◽

Cited By ~ 52

Author(s):

Jianzhong An ◽

Srinivasan G. Varadarajan ◽

Amadou Camara ◽

Qun Chen ◽

Enis Novalija ◽

...

Keyword(s):

Guinea Pig ◽

Infarct Size ◽

Reperfusion Injury ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Ringer Solution ◽

Left Ventricular ◽

Isolated Hearts ◽

Intracellular Ca ◽

Ionic Basis

We determined in intact hearts whether inhibition of Na+/H+ exchange (NHE) decreases intracellular Na+ and Ca2+ during ischemia and reperfusion, improves function during reperfusion, and reduces infarct size. Guinea pig isolated hearts were perfused with Krebs-Ringer solution at 37°C. Left ventricular (LV) free wall intracellular Na+ concentration ([Na+]i) and intracellular Ca2+ concentration ([Ca2+]i) were measured using fluorescence dyes. Hearts were exposed to 30 min of ischemia with or without 10 μM of benzamide (BIIB-513), a selective NHE-1 inhibitor, infused for 10 min just before ischemia or for 10 min immediately on reperfusion. At 2 min of reperfusion, BIIB-513 given before ischemia decreased peak increases in [Na+]i and [Ca2+]i, respectively, from 2.5 and 2.3 times (controls) to 1.6 and 1.3 times preischemia values. At 30 min of reperfusion, BIIB-513 increased systolic-diastolic LV pressure (LVP) from 49 ± 2% (controls) to 80 ± 2% of preischemia values. BIIB-513 reduced ventricular fibrillation by 54% and reduced infarct size from 64 ± 1% to 20 ± 3%. First derivative of the LVP, O2 consumption, and cardiac efficiency were also improved by BIIB-513. Similar results were obtained with BIIB-513 given on reperfusion. These data show that Na+ loading is a marker of reperfusion injury in intact hearts in that inhibiting NHE reduces Na+ and Ca2+ loading during reperfusion while improving function. These results clearly implicate the ionic basis by which inhibiting NHE protects the guinea pig intact heart from ischemia-reperfusion injury.

Download Full-text

Milrinone-Induced Pharmacological Preconditioning in Cardioprotection: Hints for a Role of Mitochondrial Mechanisms

Journal of Clinical Medicine ◽

10.3390/jcm8040507 ◽

2019 ◽

Vol 8 (4) ◽

pp. 507 ◽

Cited By ~ 7

Author(s):

Raupach ◽

Reinle ◽

Stroethoff ◽

Mathes ◽

Heinen ◽

...

Keyword(s):

Infarct Size ◽

Mitochondrial Permeability Transition ◽

Permeability Transition Pore ◽

Permeability Transition ◽

Triphenyltetrazolium Chloride ◽

Isolated Hearts ◽

Mitochondrial Signaling ◽

Infarct Size Reduction ◽

Male Wistar Rats ◽

Ros Scavenger

The activation of mitochondrial calcium-sensitive potassium (mBKCa) channels is crucially involved in cardioprotection induced by preconditioning. For milrinone (Mil)-induced preconditioning, the involvement of mBKCa-channels and further mitochondrial signaling is unknown. We hypothesize that (1) Mil-induced preconditioning is concentration-dependent and (2) that the activation of mBKCa-channels, release of reactive oxygen species (ROS), and the mitochondrial permeability transition pore (mPTP) could be involved. Isolated hearts of male Wistar rats were perfused with Krebs-Henseleit buffer and underwent 33 min of ischemia followed by 60 min of reperfusion. For determination of a concentration-dependent effect of Mil, hearts were perfused with different concentrations of Mil (0.3–10 µM) over 10 min before ischemia. In a second set of experiments, in addition to controls, hearts were pretreated with the lowest protective concentration of 1 µM Mil either alone or combined with the mBKCa-channel blocker paxilline (Pax + Mil), or paxilline alone (Pax). In additional groups, Mil was administered with and without the ROS scavenger N-2-mercaptopropionylglycine (MPG + Mil, MPG) or the mPTP inhibitor cyclosporine A (MPG + Mil + CsA, CsA + Mil), respectively. Infarct sizes were determined by triphenyltetrazolium chloride (TTC) staining. The lowest and most cardioprotective concentration was 1 µM Mil (Mil 1: 32 ± 6%; p < 0.05 vs. Con: 63 ± 8% and Mil 0.3: 49 ± 6%). Pax and MPG blocked the infarct size reduction of Mil (Pax + Mil: 53 ± 6%, MPG + Mil: 59 ± 7%; p < 0.05 vs. Mil: 34 ± 6%) without having an effect on infarct size when administered alone (Pax: 53 ± 7%, MPG: 58 ± 5%; ns vs. Con). The combined administration of CsA completely restored the MPG-inhibited cardioprotection of Mil (MPG + Mil + CsA: 35 ± 7%, p < 0.05 vs. MPG + Mil). Milrinone concentration-dependently induces preconditioning. Cardioprotection is mediated by the activation of mBKCa-channels, release of ROS and mPTP inhibition.

Download Full-text

NovelN6-substituted adenosine 5′-N-methyluronamides with high selectivity for human adenosine A3receptors reduce ischemic myocardial injury

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00411.2003 ◽

2003 ◽

Vol 285 (6) ◽

pp. H2780-H2787 ◽

Cited By ~ 31

Author(s):

W. Ross Tracey ◽

William P. Magee ◽

Joseph J. Oleynek ◽

Roger J. Hill ◽

Andrew H. Smith ◽

...

Keyword(s):

Carboxylic Acid ◽

Infarct Size ◽

Ischemia Reperfusion ◽

Receptor Activation ◽

Rate Pressure Product ◽

Receptor Selectivity ◽

Isolated Hearts ◽

Selective Agonists ◽

Langendorff Hearts

We recently reported the identification of a novel human adenosine A3receptor-selective agonist, (2 S,3 S,4 R,5 R)-3-amino-5-{6-[5-chloro-2-(3-methylisoxazol-5-ylmethoxy)benzylamino]purin-9-yl}-4-hydroxytetrahydrofuran-2-carboxylic acid methylamide (CP-608,039), with 1,260-fold selectivity for the human A3versus human A1receptor (DeNinno et al., J Med Chem 46: 353–355, 2003). However, because the modest (20-fold) rabbit A3receptor selectivity of CP-608,039 precludes demonstration of A3-mediated cardioprotection in rabbit models, we identified another member of this class, (2 S,3 S,4 R,5 R)-3-amino-5-[6-(2,5-dichlorobenzylamino)purin-9-yl]-4-hydroxytetrahydrofuran-2-carboxylic acid methylamide (CP-532,903), which both retained human A3receptor selectivity (210-fold; human A3/human A1Ki: 23/4,800 nM) and had improved rabbit A3receptor selectivity (90-fold; rabbit A3/rabbit A1Ki: 23/2,000 nM). Infarct size was measured in Langendorff hearts or in vivo after 30 min of regional ischemia and 120 min of reperfusion. Five-minute perfusion with CP-532,903 before ischemia-reperfusion elicited a concentration-dependent reduction in infarct size in isolated hearts (EC50: 0.97 nM; maximum reduction in infarct size: 77%, P < 0.05 vs. control). Furthermore, administration of CP-532,903 (150 nM) at reperfusion also significantly reduced infarct size by 64% ( P < 0.05 vs. control), which was not different ( P ≥ 0.05) from the cardioprotection provided by the same concentration of drug given before ischemia. The selective rabbit A1receptor antagonist BWA1433 did not affect CP-532,903-dependent cardioprotection. In vivo, CP-532,903 (1 mg/kg) reduced infarct size by 50% in the absence of significant hemodynamic effects (mean arterial pressure, heart rate, rate-pressure product). CP-532,903 and CP-608,039 represent a novel class of human A3receptor-selective agonists that may prove suitable for investigation of the clinical cardioprotective efficacy of A3receptor activation.

Download Full-text

Exposure of rats to hyperoxia enhances relaxation of isolated aortic rings and reduces infarct size of isolated hearts

Acta Physiologica Scandinavica ◽

10.1046/j.1365-201x.2002.01002.x ◽

2002 ◽

Vol 175 (4) ◽

pp. 271-277 ◽

Cited By ~ 14

Author(s):

P. Tähepõld ◽

P. Elfström ◽

I. Eha ◽

J. Kals ◽

G. Taal ◽

...

Keyword(s):

Infarct Size ◽

Isolated Hearts

Download Full-text

Effluent from ischemic preconditioned hearts confers cardioprotection independent of the number of preconditioning cycles

PLoS ONE ◽

10.1371/journal.pone.0243220 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0243220

Author(s):

Katharina Feige ◽

Annika Raupach ◽

Carolin Torregroza ◽

Jan Muehlenbernd ◽

Martin Stroethoff ◽

...

Keyword(s):

Myocardial Ischemia ◽

Infarct Size ◽

Ischemic Preconditioning ◽

Rat Heart ◽

Myocardial Protection ◽

Wistar Rats ◽

Isolated Hearts ◽

Infarct Size Reduction ◽

Male Wistar Rats ◽

Krebs Henseleit Buffer

Coronary effluent collected from ischemic preconditioning (IPC) treated hearts induces myocardial protection in non-ischemic-preconditioned hearts. So far, little is known about the number of IPC cycles required for the release of cardioprotective factors into the coronary effluent to successfully induce cardioprotection. This study investigated the cardioprotective potency of effluent obtained after various IPC cycles in the rat heart. Experiments were performed on isolated hearts of male Wistar rats, mounted onto a Langendorff system and perfused with Krebs-Henseleit buffer. In a first part, effluent was taken before (Con) and after each IPC cycle (Eff 1, Eff 2, Eff 3). IPC was induced by 3 cycles of 5 min of global myocardial ischemia followed by 5 minutes of reperfusion. In a second part, hearts of male Wistar rats were randomized to four groups (each group n = 4–5) and underwent 33 min of global ischemia followed by 60 min of reperfusion. The previously obtained coronary effluent was administered for 10 minutes before ischemia as a preconditioning stimulus. Infarct size was determined at the end of reperfusion by triphenyltetrazoliumchloride (TTC) staining. Infarct size with control effluent was 54±12%. Effluent obtained after IPC confers a strong infarct size reduction independent of the number of IPC cycles (Eff 1: 27±5%; Eff 2: 35±7%; Eff 3: 35±8%, each P<0.05 vs. Con). Effluent extracted after one cycle IPC is comparably protective as after two or three cycles IPC.

Download Full-text

Effect of aging on the ability of preconditioning to protect rat hearts from ischemia-reperfusion injury

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.2001.281.4.h1630 ◽

2001 ◽

Vol 281 (4) ◽

pp. H1630-H1636 ◽

Cited By ~ 113

Author(s):

Daniel Schulman ◽

David S. Latchman ◽

Derek M. Yellon

Keyword(s):

Infarct Size ◽

Rat Heart ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Middle Aged ◽

Aged Rat ◽

Isolated Hearts ◽

Regional Ischemia ◽

Kinase C ◽

Rat Hearts

Ischemic preconditioning (IP) reduces infarct size in young animals; however, its impact on aging is underinvestigated. The effect of variations in IP stimuli was studied in young, middle-aged, and aged rat hearts. Isolated hearts underwent 35 min of regional ischemia and 120 min of reperfusion. Hearts with IP were subjected to either one ischemia-reperfusion cycle (5 min of ischemia and 5 min of reperfusion per cycle) or three successive cycles before 35 min of regional ischemia. Additional studies investigated the effects of pharmacological preconditioning in aged hearts using the adenosine A1 receptor agonist 2-chloro- N 6-cyclopentyladenosine, the protein kinase C analog 1,2-dioctanoyl- sn-glycerol, and the mitochondrial ATP-sensitive potassium (KATP)-channel opener diazoxide. Infarct sizes indicated that the aged rat heart could not be preconditioned via ischemic or pharmacological means. The middle-aged rat heart had a blunted IP response compared with the young adult (only an increased IP stimulus caused a significant reduction in infarct size). These results suggest that there are defects within the IP signaling cascade of the aged heart. Clinical relevance is important if we are to use any IP-like mimetics to the benefit of an aging population.

Download Full-text

Sevoflurane Preconditioning before Moderate Hypothermic Ischemia Protects against Cytosolic [Ca2+] Loading and Myocardial Damage in Part via Mitochondrial KATPChannels

Anesthesiology ◽

10.1097/00000542-200210000-00025 ◽

2002 ◽

Vol 97 (4) ◽

pp. 912-920 ◽

Cited By ~ 22

Author(s):

Qun Chen ◽

Amadou K. S. Camara ◽

Jianzhong An ◽

Enis Novalija ◽

Matthias L. Riess ◽

...

Keyword(s):

Cardiac Function ◽

Infarct Size ◽

Fluorescence Probe ◽

Myocardial Damage ◽

Left Ventricular ◽

Global Ischemia ◽

Cardiac Efficiency ◽

Isolated Hearts ◽

Anesthetic Preconditioning ◽

Sevoflurane Preconditioning

Background Brief sevoflurane exposure and washout (sevoflurane preconditioning [SPC]) before 30-min global ischemia at 37 degrees C is known to improve cardiac function, decrease cytosolic [Ca(2+)] loading, and reduce infarct size on reperfusion. It is not known if anesthetic preconditioning (APC) applies as well to hypothermic ischemia and reperfusion and if K(ATP) channels are involved. The authors examined in guinea pig isolated hearts the effect of sevoflurane exposure before 4-h global ischemia at 17 degrees C on cardiac function, cytosolic [Ca(2+)] loading, and infarct size. In addition they tested the potential role of the mitochondrial K(ATP) channel in eliciting the cardioprotection by SPC. Methods Hearts were randomly assigned to (1) a nontreated hypothermic ischemia group (CON), (2) a group given 3.5 vol% sevoflurane for 15 min with a 15-min washout before hypothermic ischemia (SPC), and (3) an SPC group in which anesthetic exposure was bracketed with 200 microm 5-hydroxydecanoate (5-HD) from 5 min before until 5 min after sevoflurane (SPC + 5-HD). Cytosolic [Ca(2+)] was measured in the left ventricular (LV) free wall with the intracellularly loaded fluorescence probe indo-1. Results Initial reperfusion in CON hearts markedly increased systolic and diastolic [Ca(2+)] and reduced contractility (dLVP/dt(max)), relaxation (diastolic LVP, dLVP/dt(min)), myocardial oxygen consumption (MvO(2)), and cardiac efficiency. In SPC hearts, cytosolic [Ca(2+)] overloading (especially diastolic [Ca(2+)]) was decreased with increased myocardial [Ca(2+)] influx (d[Ca(2+)]/dt(max)) and efflux (d[Ca(2+)]/dt(min)), improved contractility, relaxation, coronary flow, MvO(2), cardiac efficiency, and decreased infarct size. In SPC + 5HD hearts, the reduction in infarct size was antagonized by 5-HD, but functional return was less affected by 5-HD. Conclusions Anesthetic preconditioning occurs after long-term hypothermic ischemia, and the infarct size reduction is the result, in part, of mitochondrial K(ATP) channel opening.

Download Full-text

Preconditioning with Sevoflurane Reduces Changes in Nicotinamide Adenine Dinucleotide during Ischemia–Reperfusion in Isolated Hearts

Anesthesiology ◽

10.1097/00000542-200302000-00019 ◽

2003 ◽

Vol 98 (2) ◽

pp. 387-395 ◽

Cited By ~ 38

Author(s):

Matthias L. Riess ◽

Enis Novalija ◽

Amadou K. S. Camara ◽

Janis T. Eells ◽

Qun Chen ◽

...

Keyword(s):

Infarct Size ◽

Nicotinamide Adenine Dinucleotide ◽

Ischemia Reperfusion ◽

Nicotinamide Adenine ◽

K Channel ◽

Isolated Hearts ◽

Anesthetic Preconditioning ◽

Channel Opening ◽

Rate Of Decline ◽

Improved Function

Background Ischemia causes an imbalance in mitochondrial metabolism and accumulation of nicotinamide adenine dinucleotide (NADH). We showed that anesthetic preconditioning (APC), like ischemic preconditioning, improved mitochondrial NADH energy balance during ischemia and improved function and reduced infarct size on reperfusion. Opening adenosine triphosphate-sensitive potassium (K(atp)) channels may be involved in triggering APC. The authors tested if effects of APC on NADH concentrations before, during, and after ischemia are reversible by 5-hydroxydecanoate (5-HD), a putative mitochondrial K channel blocker. Methods Nicotinamide adenine dinucleotide fluorescence was measured in 60 guinea pig Langendorff-prepared hearts assigned into five groups: (1) no treatment before ischemia; (2) APC by exposure to 1.3 mm sevoflurane for 15 min; (3) 200 microm 5-HD from 5 min before to 15 min after sevoflurane exposure; (4) 35 min 5-HD alone; and (5) no treatment and no ischemia. Sevoflurane was washed out for 30 min, and 5-HD for 15 min, before 30-min ischemia and 120-min reperfusion. Results Nicotinamide adenine dinucleotide was reversibly increased during sevoflurane exposure before ischemia, and the increase and rate of decline in NADH during ischemia were reduced after APC. 5-HD abolished these changes in NADH. On reperfusion, function was improved and infarct size reduced after APC compared with other groups. Conclusion Anesthetic preconditioning was evidenced by improved mitochondrial bioenergetics as assessed from NADH concentrations during ischemia and by attenuated reperfusion injury. Reversal of APC by bracketing sevoflurane exposure with 5-HD suggests that APC is triggered by mitochondrial K channel opening or, alternatively, by attenuated mitochondrial respiration without direct involvement of mitochondrial K channel opening.

Download Full-text