Chemical preconditioning with 3-nitropropionic acid in hearts: role of mitochondrial KATP channel

2001 ◽  
Vol 280 (5) ◽  
pp. H2406-H2411 ◽  
Author(s):  
Ramzi A. Ockaili ◽  
Peeyush Bhargava ◽  
Rakesh C. Kukreja
Keyword(s):  
Infarct Size ◽  
Early Phase ◽  
Ischemia Reperfusion ◽  
Late Phase ◽  
Saline Group ◽  
Risk Area ◽  
Nitropropionic Acid ◽  
Delayed Phase ◽  
3 Nitropropionic Acid

We investigated the cardioprotective effect of 3-nitropropionic acid (3-NPA), an inhibitior of mitochondrial succinate dehydrogenase, and we wanted to show whether this protection is mediated by of opening mitochondrial ATP-sensitive potassium (KATP) channels. Adult rabbits were treated with either 3-NPA (3 mg/kg iv) or saline ( n = 6 rabbits/group). After 30 min (for early phase) or 24 h (for late phase) of the treatment, the animals were subjected to 30 min of ischemia and 3 h of reperfusion (ischemia-reperfusion). 5-Hydroxydecanoate (5-HD, 5 mg/kg iv),the mitochondrial KATP channel blocker, was administered 10 min before ischemia-reperfusion in the saline- and 3-NPA-treated rabbits. 3-NPA caused a decrease in the infarct size from 27.8 ± 4.2% in the saline group to 16.5 ± 1.0% in the 3-NPA-treated rabbits during early phase and from 30.4 ± 4.2% in the saline group to 17.6 ± 1.05 in the 3-NPA group during delayed phase ( P < 0.05, % of risk area). The anti-infarct effect of 3-NPA was blocked by 5-HD as shown by an increase in infarct size to 33 ± 2.7% (early phase) and 31 ± 2.4% (delayed phase) ( P < 0.05 vs. 3-NPA groups). 5-HD had no proischemic effect in control animals. Also, 3-NPA had no effect on systemic hemodynamics. We conclude that 3-NPA induces long-lasting anti-ischemic effects via opening of mitochondrial KATP channels.

Sildenafil (Viagra) induces powerful cardioprotective effect via opening of mitochondrial KATPchannels in rabbits

2002 ◽  
Vol 283 (3) ◽  
pp. H1263-H1269 ◽  
Author(s):  
Ramzi Ockaili ◽  
Fadi Salloum ◽  
John Hawkins ◽  
Rakesh C. Kukreja
Keyword(s):  
Infarct Size ◽  
Acute Phase ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cardioprotective Effect ◽  
Sildenafil Citrate ◽  
Protective Effects ◽  
Risk Area ◽  
Arterial Blood ◽  
Delayed Phase

Sildenafil citrate (Viagra) is the pharmacological agent used to treat erectile dysfunction in men. Because this drug has a vasodilatory effect, we hypothesized that such an action may induce a preconditioning-like cardioprotective effect via opening of mitochondrial ATP-sensitive K (KATP) channels. Rabbits were treated with sildenafil citrate (0.7 mg/kg iv) either 30 min (acute phase) or 24 h (delayed phase) before 30 min of ischemia and 3 h of reperfusion. Mitochondrial KATPchannel blocker 5-hydroxydecanoate (5-HD, 5 mg/kg iv) was given 10 min before ischemia-reperfusion. Infarct size was measured by tetrazolium staining. Sildenafil caused reduction in arterial blood pressure within 2 min of treatment, which returned to nearly baseline levels 3 min later. The infarct size (% risk area, means ± SE) reduced from 33.8 ± 1.7 in control rabbits to 10.8 ± 0.9 during the acute phase (68% reduction, P < 0.05) and 19.9 ± 2.0 during the delayed phase (41% reduction, P < 0.05). 5-HD abolished protection with an increase in infarct size to 35.6 ± 0.4% and 36.8 ± 1.6% during the acute and delayed phase, respectively ( P < 0.05). Similar acute and delayed cardioprotective effects were observed when sildenafil was administered orally. Systemic hemodynamics also decreased after oral administration of the drug. However, these changes were mild and occurred slowly. For the first time, we demonstrate that sildenafil induces acute and delayed protective effects against ischemia-reperfusion injury, which are mediated by opening of mitochondrial KATPchannels.

scholarly journals Dual role of MUC1 mucin in kidney ischemia-reperfusion injury: Nephroprotector in early phase, but pro-fibrotic in late phase

2017 ◽  
Vol 1863 (6) ◽  
pp. 1336-1349 ◽  
Author(s):  
Jean-Baptiste Gibier ◽  
Brigitte Hémon ◽  
Mélanie Fanchon ◽  
Kelly Gaudelot ◽  
Nicolas Pottier ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Early Phase ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Late Phase ◽  
Dual Role ◽  
Muc1 Mucin ◽  
Kidney Ischemia

Cyclooxygenase-2 does not mediate late preconditioning induced by activation of adenosine A1 or A3receptors

2001 ◽  
Vol 281 (2) ◽  
pp. H959-H968 ◽  
Author(s):  
Eitaro Kodani ◽  
Ken Shinmura ◽  
Yu-Ting Xuan ◽  
Hitoshi Takano ◽  
John A. Auchampach ◽  
...  
Keyword(s):  
Infarct Size ◽  
Receptor Agonist ◽  
Coronary Occlusion ◽  
Late Phase ◽  
Cyclooxygenase 2 ◽  
Late Preconditioning ◽  
Cardioprotective Effects ◽  
Cox 2 ◽  
Delayed Phase

Recent studies have demonstrated that the adenosine A1 receptor agonist 2-chloro- N 6-cyclopentyladenosine (CCPA) and the adenosine A3 receptor agonist N 6-(3-iodobenzyl)adenosine-5′- N-methyluronamide (IB-MECA) produce a delayed phase of protection against infarction similar to the late phase of ischemic preconditioning (PC). However, the mechanism for adenosine A1 or A3receptor-induced late PC remains unknown. The goal of this study was to determine whether the delayed cardioprotective effects of adenosine A1 or A3 receptors are mediated by cyclooxygenase-2 (COX-2), which is an obligatory mediator of ischemic PC. We found that COX-2 protein expression (Western blotting) did not increase 24 h after the administration of either CCPA (100 μg/kg iv) or IB-MECA (300 μg/kg iv) compared with controls. To probe the role of constitutive COX-2 expression, conscious rabbits were subjected to 30-min coronary occlusion followed by 72-h reperfusion. Twenty-four hours before the occlusion, the rabbits were pretreated with CCPA (100 μg/kg iv) or IB-MECA (300 μg/kg iv). Both CCPA and IB-MECA resulted in a marked (∼47%) reduction in infarct size vs. controls [36.2 ± 4.0% of the risk region ( n = 9), 31.2 ± 4.7% ( n = 9), and 59.5 ± 3.8% ( n = 9), respectively; P < 0.05], similar to that induced by the late phase of ischemic PC [31.8 ± 3.2% ( n = 9)]. The selective COX-2 inhibitor N-(2-[cyclohexyloxy]4-nitrophenyl)methanesulfonamide (NS-398, 5 mg/kg), which abolished the protective effect of ischemic late PC, failed to block the protection of either CCPA or IB-MECA, indicating that COX-2 does not mediate the delayed protection of either CCPA or IB-MECA [CCPA + NS-398, 29.1 ± 3.4% ( n = 7); IB-MECA + NS-398, 34.9 ± 2.9% ( n = 8)]. NS-398 in itself did not affect infarct size [54.9 ± 3.7% ( n = 9)]. Taken together, these results demonstrate that, in contrast to ischemia-induced late PC, the mechanisms of adenosine A1 or A3 receptor-induced late PC is independent of COX-2.

Protein kinase C plays an essential role in sildenafil-induced cardioprotection in rabbits

2004 ◽  
Vol 286 (4) ◽  
pp. H1455-H1460 ◽  
Author(s):  
Anindita Das ◽  
Ramzi Ockaili ◽  
Fadi Salloum ◽  
Rakesh C. Kukreja
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Infarct Size ◽  
Essential Role ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Sildenafil Citrate ◽  
Risk Area ◽  
Kinase C

Sildenafil citrate (Viagra) is the most widely used pharmacological drug for treating erectile dysfunction in men. It has potent cardioprotective effects against ischemia-reperfusion injury via nitric oxide and opening of mitochondrial ATP-sensitive K+ channels. We further investigated the role of protein kinase C (PKC)-dependent signaling pathway in sildenafil-induced cardioprotection. Rabbits were treated (orally) with sildenafil citrate (1.4 mg/kg) 30 min before index ischemia for 30 min and reperfusion for 3 h. The PKC inhibitor chelerythrine (5 mg/kg iv) was given 5 min before sildenafil. Infarct size (% of risk area) reduced from 33.65 ± 2.17 in the vehicle (saline) group to 15.07 ± 0.63 in sildenafil-treated groups, a 45% reduction compared with vehicle (mean ± SE, P < 0.05). Chelerythrine abolished sildenafil-induced protection, as demonstrated by increase in infarct size to 31.14 ± 2.4 ( P < 0.05). Chelerythrine alone had an infarct size of 33.5 ± 2.5, which was not significantly different compared with DMSO-treated group (36.8 ± 1.7, P > 0.05). Western blot analysis demonstrated translocation of PKC-α, -θ, and -δ isoforms from cytosol to membrane after treatment with sildenafil. However, no change in the PKC-β and -ϵ isoforms was observed. These data provide direct evidence of an essential role of PKC, and potentially PKC-α, -θ, and -δ, in sildenafil-induced cardioprotection in the rabbit heart.

Opening of mitochondrial KATPchannel induces early and delayed cardioprotective effect: role of nitric oxide

1999 ◽  
Vol 277 (6) ◽  
pp. H2425-H2434 ◽  
Author(s):  
Ramzi Ockaili ◽  
Venkata R. Emani ◽  
Shinji Okubo ◽  
Michael Brown ◽  
Kavitha Krottapalli ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Ischemia Reperfusion ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Vehicle Group ◽  
Blue Dye ◽  
Risk Area ◽  
Tetrazolium Staining ◽  
Delayed Phase

Opening of mitochondrial ATP-sensitive (mitoKATP) channel with diazoxide induces an early phase (EP) of cardioprotection. It is unknown whether diazoxide also induces a delayed phase (DP) of cardioprotection. Because nitric oxide (NO) modulates ATP sensitivity of the KATPchannel, we hypothesized that NO may play a role in diazoxide-induced cardioprotection. Diazoxide (1 mg/kg) was administered either 30 min (for EP) or 24 h (DP) before 30 min of lethal ischemia. Blockers of mitoKATPchannel [5-hydroxydecanoate (5-HD)] or NO synthase [ NG-nitro-l-arginine methyl ester (l-NAME)] were given 10 min before ischemia-reperfusion performed by 30 min of left anterior descending coronary artery occlusion and 3 h of reperfusion. A risk area (RA) was demarcated by Evans blue dye, and infarct size (IS) was measured by tetrazolium staining. Diazoxide caused a decrease in IS (%RA) from 27.8 ± 4.2% in the vehicle group to 12.9 ± 1.2% during EP and from 30.4 ± 4.2% in vehicle-treated rabbits to 19.6 ± 2.4% during DP ( P < 0.05). IS increased to 31.3 ± 1.1% and 27.9 ± 1.0% (EP) and 29.9 ± 2.3% and 35.1 ± 1.8% (DP) with 5-HD andl-NAME, respectively ( P < 0.05). 5-HD andl-NAME caused no proischemic effect in controls. Diazoxide induced both early and delayed anti-ischemic effects via opening of mitoKATPchannels, which was NO dependent.

Ischemic preconditioning in rats: role of mitochondrial KATP channel in preservation of mitochondrial function

2000 ◽  
Vol 278 (1) ◽  
pp. H305-H312 ◽  
Author(s):  
Ryan M. Fryer ◽  
Janis T. Eells ◽  
Anna K. Hsu ◽  
Michele M. Henry ◽  
Garrett J. Gross
Keyword(s):  
Infarct Size ◽  
Ischemic Preconditioning ◽  
Mitochondrial Function ◽  
Ischemia Reperfusion ◽  
Mitochondrial Protein ◽  
Atp Synthesis ◽  
Area At Risk ◽  
Selective Antagonist ◽  
Mitochondrial Katp Channel

We examined the role of the sarcolemmal and mitochondrial KATPchannels in a rat model of ischemic preconditioning (IPC). Infarct size was expressed as a percentage of the area at risk (IS/AAR). IPC significantly reduced infarct size (7 ± 1%) versus control (56 ± 1%). The sarcolemmal KATP channel-selective antagonist HMR-1098 administered before IPC did not significantly attenuate cardioprotection. However, pretreatment with the mitochondrial KATP channel-selective antagonist 5-hydroxydecanoic acid (5-HD) 5 min before IPC partially abolished cardioprotection (40 ± 1%). Diazoxide (10 mg/kg iv) also reduced IS/AAR (36.2 ± 4.8%), but this effect was abolished by 5-HD. As an index of mitochondrial bioenergetic function, the rate of ATP synthesis in the AAR was examined. Untreated animals synthesized ATP at 2.12 ± 0.30 μmol ⋅ min−1 ⋅ mg mitochondrial protein−1. Rats subjected to ischemia-reperfusion synthesized ATP at 0.67 ± 0.06 μmol ⋅ min−1 ⋅ mg mitochondrial protein−1. IPC significantly increased ATP synthesis to 1.86 ± 0.23 μmol ⋅ min−1 ⋅ mg mitochondrial protein−1. However, when 5-HD was administered before IPC, the preservation of ATP synthesis was attenuated (1.18 ± 0.15 μmol ⋅ min−1 ⋅ mg mitochondrial protein−1). These data are consistent with the notion that inhibition of mitochondrial KATPchannels attenuates IPC by reducing IPC-induced protection of mitochondrial function.

Abstract 2894: Essential Role of ERK 1/2 in Sildenafil-Induced Early and Delayed Cardioprotection in Mice

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Anindita das ◽  
Lei Xi ◽  
Fadi N Salloum ◽  
Yuan J Rao ◽  
Rakesh C Kukreja
Keyword(s):  
South Carolina ◽  
Infarct Size ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Critical Role ◽  
Heart Association ◽  
Myocardial Infarct Size ◽  
Western Blots ◽  
Delayed Cardioprotection

Background: Sildenafil (SIL), a potent inhibitor of phosphodiesterase-5 induces powerful protection against myocardial ischemia-reperfusion (I-R) injury through activation of protein kinase G (PKG). However, the downstream targets of PKG in SIL-induced cardioprotection remain unclear. We hypothesized that PKG-dependent activation of survival kinase, ERK may play a critical role in SIL-induced cardioprotection in mice. Methods & Results: Ventricular myocytes were isolated from adult male ICR mice and exposed to 40 min of simulated ischemia (SI) with/without 1 hr pre-incubation of SIL (1 μM). Myocyte necrosis and apoptosis were determined after 1 hr or 18 hrs of reoxygenation (RO) using trypan blue or TUNEL assay, respectively. Pretreatment with SIL protected cardiomyocytes after SI-RO (necrosis 18.5±0.5% and apoptosis 6.6±0.7%; n=4, p<0.001) as compared with controls (necrosis 42.1±1.8% and apoptosis 23.3±0.9%). Co-incubation of PD98059 (20 μM), a selective ERK1/2 inhibitor blocked both anti-necrotic and anti-apoptotic protection in cardiomyocytes. Furthermore, intra-coronary infusion of SIL (1 μM) in Langendorff isolated mouse hearts 10 min prior to zero-flow global I (20 min) and R (30 min) significantly reduced myocardial infarct size (from 29.4±2.4% to 16.0±3.0%; p<0.05, n=6). Co-treatment of PD98059 abrogated SIL-induced protection (33.0±5.9; n=4). To evaluate the role of ERK1/2 in delayed cardioprotection, mice were treated with saline or SIL (0.7 mg/kg i.p.) 24 hours before global I-R in Langendorff mode. PD98059 (1 mg/kg) was administered (i.p.) 30 min before the treatment of SIL. Infarct size was reduced from 27.6±3.3% in saline-treated controls to 6.9±1.2% in SIL-treated mice (P<0.05, n=6). The delayed protective effect of SIL was also abolished by PD98059 (22.5±2.3%). Western Blots revealed that SIL significantly increased phosphorylation of ERK1/2 which was blocked by PKG inhibitor, KT5823 in the heart and adult myocytes. Selective knockdown of PKG in cardiomyocytes with short hairpin RNA of PKG also blocked the phosphorylation of ERK1/2. Conclusion: SIL-induced cardioprotection involves the activation and phosphorylation of ERK which appear to be intimately linked with a PKG-dependent survival pathway. This research has received full or partial funding support from the American Heart Association, AHA Mid-Atlantic Affiliate (Maryland, North Carolina, South Carolina, Virginia & Washington, DC).

Abstract 424: Activation of the S1P3 Receptors is Responsible for S1P-mediated RhoA Activation and Cardioprotection

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Bryan S Yung ◽  
Sunny Y Xiang ◽  
Nicole Purcell ◽  
Hugh Rosen ◽  
Jerold Chun ◽  
...  
Keyword(s):  
Infarct Size ◽  
Ischemia Reperfusion ◽  
Cardiovascular Responses ◽  
Neonatal Rat ◽  
Receptor Subtype ◽  
Receptor Subtypes ◽  
S1p Receptors ◽  
Rhoa Activation ◽  
Therapeutic Benefits

Sphingosine-1-phoshpate (S1P) is a bioactive lysophospholipid, generated and released at sites of tissue injury. S1P signals through a variety of G-protein coupled receptor subtypes and there are three major sub-types, S1P 1 , S1P 2 , and S1P 3 , to mediate cardiovascular responses. S1P 2 and S1P 3 receptors couple to Gα i , Gα 12 , Gα 13 and Gα q and we first examined the contribution of S1P 2 and S1P 3 to cardiac hypertrophy using S1P 2 and S1P 3 knockout (KO) mice and found that there is no difference in hypertrophy induced by pressure-overload. We previously showed that S1P provides cardioprotection against oxidative stress such as ischemia/reperfusion in which RhoA activation and its downstream effector PKD1 play an important role. It has not, however, been determined which S1P receptor subtype is responsible for S1P mediated cardioprotection. We knocked down the three major S1P receptors using siRNA in neonatal rat ventricular myocytes (NRVMs) and assessed RhoA and PKD1 activation induced by S1P. Knockdown of S1P 3 abolished RhoA activation and largely attenuated phosphorylation of PKD1 while knockdown of S1P 1 and S1P 2 did not. Using siRNA or pertussis toxin to inhibit different G-proteins, we further established that S1P regulates RhoA activation through Gα 13 , but not Gα 12 , Gα q , or Gα i . To investigate the role of S1P 3 receptors in the adult heart, hearts were isolated from wild-type or S1P 3 KO adult mice, perfused in the Langendorff mode and subjected to ex vivo ischemia/reperfusion. As previously reported, S1P perfusion significantly reduced infarct size induced by ischemia/reperfusion in WT hearts (by 50%), but this protection was abolished in the S1P 3 KO mouse heart. To further confirm the role of S1P 3 in cardioprotection we perfused WT mouse hearts with an S1P 3 -specific agonist CYM-51736. We observed that CYM-51736 attenuated the infarct size to a similar degree as that observed with S1P. Our findings reveal that activation of the S1P 3 receptor coupling to Gα 13 and subsequent RhoA activation is responsible for cardioprotection against ischemia/reperfusion. Accordingly specific drug targeting of S1P 3 receptors could provide therapeutic benefits in ischemic heart disease without the undesirable effects of global activation of other cardiac S1P receptors.

Abstract 16598: The Role of Paraoxonase 2 in Myocardial Ischemia/Reperfusion Injury

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Jingyuan Li ◽  
Victor R Grijalva ◽  
Srinivasa T Reddy ◽  
Mansoureh Eghbali
Keyword(s):  
Myocardial Ischemia ◽  
Infarct Size ◽  
Er Stress ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Ros Production ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion

Objectives: Paraoxonases (PON) gene family consists of three proteins PON1, PON2, and PON3. PON2 is an intracellular membrane-associated protein that is widely expressed in vascular cells and many tissues. At the subcellular level, PON2 is localized to both the ER and mitochondria, and protects against oxidative stress. Hypothesis: The aim of this study was to investigate the role of PON2 in myocardial ischemia reperfusion injury. Methods: PON2 deficient (PON2-/-) and WT male mice were subjected to in-vivo ischemia/reperfusion injury. The left anterior descending coronary artery was occluded for 30 min followed by 24 hr of reperfusion. The infarct size, mitochondrial calcium retention capacity (CRC) and reactive oxygen species (ROS) generation were measured. The expression of C/EBP homologous protein (CHOP), GSK3b and phosphate GSK3b protein were examined by Western Blot. The number of animals was 5-7/group and data were expressed as mean±SEM. T test were used for statistical analysis. Probability values <0.05 were considered statistically significant. Results: The infarct size was ~2 fold larger in PON2 deficient mice compared to WT mice (p<0.05). The threshold for opening of mitochondrial permeability transition pore (mPTP) in response to calcium overload was much lower in PON2-/- mice compared with WT mice (173±19 in PON2-/-, 250±41 in WT, nmol/mg-mitochondrial protein, p<0.05). The ROS production was ~2 fold higher in isolated cardiac mitochondria from PON2-/- mice compared with WT mice (p<0.05). ER stress protein CHOP increased significantly in PON2-/- mice compared to WT mice (normalized to WT: 1±0.05 in WT, 1.66±0.08 in PON2-/-, p<0.001). Phospho-GSK3b level was significantly downregulated in in PON2-/- mice compared to WT mice (pGSK3b/GSK3b normalized to WT: 1±0.06 in WT 0.67±0.08 in PON2-/-, p<0.05). Conclusions: PON2 regulates myocardial ischemia/reperfusion injury via inhibiting the opening of mPTP, which is associated with reduced mitochondria ROS production, deactivation of ER stress signaling CHOP and GSK3b.

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