scholarly journals 997-91 Glycogen Loading In Vivo Reverses Decreased Function After Ischemic Preconditioning In Vitro

1995 ◽  
Vol 25 (2) ◽  
pp. 327A
Author(s):  
Torsten Doenst ◽  
Patrick Guthrie ◽  
Heinrich Taegtmeyer
Keyword(s):  
Ischemic Preconditioning

Reappraisal of H2S/sulfide concentration in vertebrate blood and its potential significance in ischemic preconditioning and vascular signaling

2008 ◽  
Vol 294 (6) ◽  
pp. R1930-R1937 ◽  
Author(s):  
Nathan L. Whitfield ◽  
Edward L. Kreimier ◽  
Francys C. Verdial ◽  
Nini Skovgaard ◽  
Kenneth R. Olson
Keyword(s):  
Ischemic Preconditioning ◽  
Baseline Level ◽  
Venous Blood ◽  
Sulfide Concentration ◽  
Potential Significance ◽  
Aortic Blood ◽  
Total Sulfide ◽  
Series Of Experiments

Hydrogen sulfide (H2S) is rapidly emerging as a biologically significant signaling molecule. Studies published before 2000 report low or undetectable H2S (usually as total sulfide) levels in blood or plasma, whereas recent work has reported sulfide concentrations between 10 and 300 μM, suggesting it acts as a circulating signal. In the first series of experiments, we used a recently developed polarographic sensor to measure the baseline level of endogenous H2S gas and turnover of exogenous H2S gas in real time in blood from numerous animals, including lamprey, trout, mouse, rat, pig, and cow. We found that, contrary to recent reports, H2S gas was essentially undetectable (<100 nM total sulfide) in all animals. Furthermore, exogenous sulfide was rapidly removed from blood, plasma, or 5% bovine serum albumin in vitro and from intact trout in vivo. To determine if blood H2S could transiently increase, we measured oxygen-dependent H2S production by trout hearts in vitro and in vivo. H2S has been shown to mediate ischemic preconditioning (IPC) in mammals. IPC is present in trout and, unlike mammals, the trout myocardium obtains its oxygen from relatively hypoxic systemic venous blood. In vitro, myocardial H2S production was inversely related to Po2, whereas we failed to detect H2S in ventral aortic blood from either normoxic or hypoxic fish in vivo. These results provide an autocrine or paracrine mechanism for myocardial coupling of hypoxia to H2S in IPC, i.e., oxygen sensing, but they fail to provide any evidence that H2S signaling is mediated by the circulation.

Adenosine preconditions against endothelin-induced constriction of coronary arterioles

2000 ◽  
Vol 279 (6) ◽  
pp. H2593-H2597 ◽  
Author(s):  
Daphne Merkus ◽  
David W. Stepp ◽  
Deron W. Jones ◽  
Yasuhiro Nishikawa ◽  
William M. Chilian
Keyword(s):  
Ischemic Preconditioning ◽  
Dose Response ◽  
Response Curve ◽  
Protective Function ◽  
Vasodilatory Effect ◽  
Arteriolar Diameter ◽  
Myocardial Hypoperfusion ◽  
Coronary Arterioles

Myocardial hypoperfusion is accompanied by concomitant increases in adenosine and endothelin-1 (ET-1) production, but the vasodilatory effect of adenosine prevails over that of ET-1. Therefore, we hypothesized that adenosine-induced or ischemic preconditioning reduces the vasoconstrictive effect of ET-1. Coronary arteriolar diameter in vivo was measured using fluorescence microangiography in anesthetized open-thorax dogs. ET-1 (5 ng · kg−1 · min−1administered intracoronary, n = 10) induced progressive constriction over 45 min [25 ± 6% (SE)]. The constriction was blocked by preconditioning with adenosine (25 μg · kg−1 · min−1administered intracoronary) for 20 min and 10 min of washout ( n = 10) or attenuated by ischemic preconditioning (four 5-min periods of ischemia, 9 ± 5% at 45 min). To investigate the receptor involved in this process, coronary arterioles (50–150 μm) were isolated and pressurized at 60 mmHg in vitro. The ET-1 dose-response curve (1 pM–5 nM) was rightward shifted after preconditioning with adenosine (1 μM) for 20 min and 10 min of washout ( n = 11). Blockade of A2 receptors [8-(3-chlorostyryl)caffeine, 1 μM, n = 9] but not A1 receptors (8-cyclopentyl-1,3-dipropylxanthine, 100 nM, n = 7) prevented this shift. These results suggest that adenosine confers a vascular preconditioning effect, mediated via the A2 receptor, against endothelin-induced constriction. This effect may offer a new protective function of adenosine in preventing excessive coronary constriction.

From the S.P. Botkin’s idea of “preexposure” to preconditioning phenomenon. Perspectives for use of phenomena of ischemic and pharmacological preconditioning

2016 ◽  
Vol 14 (1) ◽  
pp. 4-28 ◽  
Author(s):  
Irina V Zarubina ◽  
Petr D Shabanov
Keyword(s):  
Ischemic Preconditioning ◽  
Acute Hypoxia ◽  
Pharmacological Agents ◽  
Late Preconditioning ◽  
Short Period ◽  
Shock Proteins ◽  
Clinical Conditions ◽  
Pharmacological Preconditioning

The phenomenon of ischemic preconditioning based on the S.P. Botkin’s idea about defense effect of disturbing factors acting in small intensities is observed in the review. The modern literature data about main types of preconditioning exposure, triggers and mechanisms of ischemic preconditioning are reviewed. This phenomenon was supported in many experiments in vivo and in vitro on animals of different spices as well as in humans in clinical conditions. Ischemic preconditioning is qualified as transient positive changes in the organs and tissues produced by activation of rapid endogenous adoptive processes in them during the short period of subletal ischemia and reperfusion and which defend them from subsequent ischemic episodes. There are early and late ischemic preconditioning (the second window of defense). The first type of ischemic preconditioning belongs to classic type of preconditioning and is produced by the short ischemic episodes (3-5 min) and similar intervals of reperfusion. Ischemic preconditioning observed in a day or more after preconditioning stimuli is named as late preconditioning with genes expression, synthesis of heat shock proteins (HSP 72 in particular) and NO synthase as the basis mechanisms underlying of it. Administration of triggers like adenosine, forbol ether, bradykinine or glycerol derivatives into the blood or ischemic tissues produces defense action similar to ischemic preconditioning and qualified as pharmacological preconditioning. Preconditioning induced by pharmacological agents are more preference than short ischemic episodes. Antihypoxic effects of benzimidazol derivatives in both an acute hypoxia and hypoxic preconditioning are described in the article. Other perspectives of pharmacological preconditioning in practical use are also discussed.

Ischemic preconditioning of the whole heart confers protection on subsequently isolated ventricular myocytes

2008 ◽  
Vol 294 (1) ◽  
pp. H524-H531 ◽  
Author(s):  
Glenn C. Rodrigo ◽  
Nilesh J. Samani
Keyword(s):  
Ischemic Preconditioning ◽  
Ventricular Myocytes ◽  
Contractile Function ◽  
Ischemia Reperfusion ◽  
Isolated Cells ◽  
Cellular Models ◽  
Whole Heart ◽  
Intact Heart

Current cellular models of ischemic preconditioning (IPC) rely on inducing preconditioning in vitro and may not accurately represent complex pathways triggered by IPC in the intact heart. Here, we show that it is possible to precondition the intact heart and to subsequently isolate individual ventricular myocytes that retain the protection triggered by IPC. Myocytes isolated from Langendorff-perfused hearts preconditioned with three cycles of ischemia-reperfusion were exposed to metabolic inhibition and reenergization. Injury was assessed from induction of hypercontracture and loss of Ca2+ homeostasis and contractile function. IPC induced an immediate window of protection in isolated myocytes, with 64.3 ± 7.6% of IPC myocytes recovering Ca2+ homeostasis compared with 16.9 ± 2.4% of control myocytes ( P < 0.01). Similarly, 64.1 ± 5.9% of IPC myocytes recovered contractile function compared with 15.3 ± 2.2% of control myocytes ( P < 0.01). Protection was prevented by the presence of 0.5 mM 5-hydroxydecanoate during the preconditioning stimulus. This early protection disappeared after 6 h, but a second window of protection developed 24 h after preconditioning, with 54.9 ± 4.7% of preconditioned myocytes recovering Ca2+ homeostasis compared with 12.6 ± 2.9% of control myocytes ( P < 0.01). These data show that “true” IPC of the heart confers both windows of protection in the isolated myocytes, with a similar temporal relationship to in vivo preconditioning of the whole heart. The model should allow future studies in isolated cells of the protective mechanisms induced by true ischemia.

scholarly journals Prevention of Kidney Ischemia/Reperfusion-induced Functional Injury and JNK, p38, and MAPK Kinase Activation by Remote Ischemic Pretreatment

2001 ◽  
Vol 276 (15) ◽  
pp. 11870-11876 ◽  
Author(s):  
Kwon Moo Park ◽  
Ang Chen ◽  
Joseph V. Bonventre
Keyword(s):  
Cell Fate ◽  
Ischemic Preconditioning ◽  
Ischemia Reperfusion ◽  
Ischemic Injury ◽  
Prior Exposure ◽  
Ischemic Insult ◽  
Subsequent Increase ◽  
Fractional Excretion Of Sodium

MAPK activities, including JNK, p38, and ERK, are markedly enhanced after ischemiain vivoand chemical anoxiain vitro. The relative extent of JNK, p38, or ERK activation has been proposed to determine cell fate after injury. A mouse model was established in which prior exposure to ischemia protected against a second ischemic insult imposed 8 or 15 days later. In contrast to what was observed after 30 min of bilateral ischemia, when a second period of ischemia of 30- or 35-min duration was imposed 8 days later, there was no subsequent increase in plasma creatinine, decrease in glomerular filtration rate, or increase in fractional excretion of sodium. A shorter period of prior ischemia (15 min) was partially protective against subsequent ischemic injury 8 days later. Unilateral ischemia was also protective against a subsequent ischemic insult to the same kidney, revealing that systemic uremia is not necessary for protection. The ischemia-related activation of JNK and p38 and outer medullary vascular congestion were markedly mitigated by prior exposure to ischemia, whereas preconditioning had no effect on post-ischemic activation of ERK1/2. The phosphorylation of MKK7, MKK4, and MKK3/6, upstream activators of JNK and p38, was markedly reduced by ischemic preconditioning, whereas the post-ischemic phosphorylation of MEK1/2, the upstream activator of ERK1/2, was unaffected by preconditioning. Pre- and post-ischemic HSP-25 levels were much higher in the preconditioned kidney. In summary, post-ischemic JNK and p38 (but not ERK1/2) activation was markedly reduced in a model of kidney ischemic preconditioning that was established in the mouse. The reduction in JNK and p38 activation can be accounted for by reduced activation of upstream MAPK kinases. The post-ischemic activation patterns of MAPKs may explain the remarkable protection against ischemic injury observed in this model.

GATA3 (GATA-Binding Protein 3)/KMT2A (Lysine-Methyltransferase-2A) Complex by Increasing H3K4-3me (Trimethylated Lysine-4 of Histone-3) Upregulates NCX3 (Na + -Ca 2+ Exchanger 3) Transcription and Contributes to Ischemic Preconditioning Neuroprotection

Stroke ◽  
2021 ◽  
Vol 52 (11) ◽  
pp. 3680-3691
Author(s):  
Natascia Guida ◽  
Luigi Mascolo ◽  
Angelo Serani ◽  
Ornella Cuomo ◽  
Serenella Anzilotti ◽  
...  
Keyword(s):  
Ischemic Preconditioning ◽  
Cortical Neurons ◽  
Promoter Region ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Histone 3 ◽  
Lysine Methyltransferase ◽  
Cerebral Artery Occlusion

Background and Purpose: NCX3 (Na + -Ca 2+ exchanger 3) plays a relevant role in stroke; indeed its pharmacological blockade or its genetic ablation exacerbates brain ischemic damage, whereas its upregulation takes part in the neuroprotection elicited by ischemic preconditioning. To identify an effective strategy to induce an overexpression of NCX3, we examined transcription factors and epigenetic mechanisms potentially involved in NCX3 gene regulation. Methods: Brain ischemia and ischemic preconditioning were induced in vitro by exposure of cortical neurons to oxygen and glucose deprivation plus reoxygenation (OGD/Reoxy) and in vivo by transient middle cerebral artery occlusion. Western blot and quantitative real-time polymerase chain reaction were used to evaluate transcripts and proteins of GATA3 (GATA-binding protein 3), KMT2A (lysine-methyltransferase-2A), and NCX3. GATA3 and KMT2A binding on NCX3 gene was evaluated by chromatin immunoprecipitation and Rechromatin immunoprecipitation experiments. Results: Among the putative transcription factors sharing a consensus sequence on the ncx3 brain promoter region, GATA3 was the only able to up-regulate ncx3. Interestingly, GATA3 physically interacted with KMT2A, and their overexpression or knocking-down increased or downregulated NCX3 mRNA and protein, respectively. Notably, site-direct mutagenesis of GATA site on ncx3 brain promoter region counteracted GATA3 and KMT2A binding on NCX3 gene. More importantly, we found that in the perischemic cortical regions of preconditioned rats GATA3 recruited KMT2A and the complex H3K4-3me (trimethylated lysine-4 of histone-3) on ncx3 brain promoter region, thus reducing transient middle cerebral artery occlusion–induced damage. Consistently, in vivo silencing of either GATA3 or KMT2A prevented NCX3 upregulation and consequently the neuroprotective effect of preconditioning stimulus. The involvement of GATA3/KMT2A complex in neuroprotection elicited by ischemic preconditioning was further confirmed by in vitro experiments in which the knocking-down of GATA3 and KMT2A reverted the neuroprotection induced by NCX3 overexpression in cortical neurons exposed to anoxic preconditioning followed by oxygen and glucose deprivation plus reoxygenation. Conclusions: Collectively, our results revealed that GATA3/KMT2A complex epigenetically activates NCX3 gene transcription during ischemic preconditioning.

scholarly journals Activation of Nrf2-Regulated Glutathione Pathway Genes by Ischemic Preconditioning

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Karen F. S. Bell ◽  
Jill H. Fowler ◽  
Bashayer Al-Mubarak ◽  
Karen Horsburgh ◽  
Giles E. Hardingham
Keyword(s):  
Ischemic Preconditioning ◽  
Target Genes ◽  
Neuronal Loss ◽  
Antioxidant Defences ◽  
Glutathione Biosynthesis ◽  
Human Astrocytes ◽  
Glutathione Pathway

Prophylactic pharmacological activation of astrocytic gene expression driven by the transcription factor Nrf2 boosts antioxidant defences and protects against neuronal loss in ischemia and other disease models. However, the role of Nrf2 in mediating endogenous neuroprotective responses is less clear. We recently showed that Nrf2 is activated by mild oxidative stress in both rodent and human astrocytes. Moreover, brief exposure to ischemic conditions was found to activate Nrf2 bothin vivoandin vitro, and this was found to contribute to neuroprotective ischemic preconditioning. Here we show that transient ischemic conditionsin vitroandin vivocause an increase in the expression of Nrf2 target genes associated with the glutathione pathway, including those involved in glutathione biosynthesis and cystine uptake. Taken together, these studies indicate that astrocytic Nrf2 may represent an important mediator of endogenous neuroprotective preconditioning pathways.

scholarly journals Effects of Cerebral Ischemia on Neuronal Hemoglobin

2008 ◽  
Vol 29 (3) ◽  
pp. 596-605 ◽  
Author(s):  
Yangdong He ◽  
Ya Hua ◽  
Wenquan Liu ◽  
Haitao Hu ◽  
Richard F Keep ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Ischemic Preconditioning ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Sprague Dawley ◽  
Cerebral Neurons

This study examined whether neuronal hemoglobin (Hb) is present in rats. It then examined whether cerebral ischemia or ischemic preconditioning (IPC) affects neuronal Hb levels in vivo and in vitro. In vivo, male Sprague-Dawley rats were subjected to either 15 mins of transient middle cerebral artery occlusion (MCAO) with 24 h of reperfusion, an IPC stimulus, or 24 h of permanent MCAO (pMCAO), or IPC followed 3 days later by 24 h of pMCAO. In vitro, primary cultured neurons were exposed to 2 h of oxygen—glucose deprivation (OGD) with 22 h of reoxygenation. Results showed that Hb is widely expressed in rat cerebral neurons but not astrocytes. Hemoglobin expression was significantly upregulated in the ipsilateral caudate and the cortical core of the middle cerebral artery territory after IPC. Hemoglobin levels also increased more in the penumbral cortex and the contralateral hemisphere 24 h after pMCAO, but expressions in the ipsilateral caudate and the cortical core area were decreased. Ischemic preconditioning modified pMCAO-induced brain Hb changes. Neuronal Hb levels in vitro were increased by 2 h of OGD and 22 h of reoxygenation. These results indicate that Hb is synthesized in neurons and can be upregulated by ischemia.

scholarly journals Influence of Hyperglycemia and Diabetes on Cardioprotection by Humoral Factors Released after Remote Ischemic Preconditioning (RIPC)

2021 ◽  
Vol 22 (16) ◽  
pp. 8880
Author(s):  
Carolin Torregroza ◽  
Lara Gnaegy ◽  
Annika Raupach ◽  
Martin Stroethoff ◽  
Katharina Feige ◽  
...  
Keyword(s):  
Infarct Size ◽  
Ischemic Preconditioning ◽  
Ischemia Reperfusion ◽  
Experimental Studies ◽  
Limb Ischemia ◽  
Remote Ischemic Preconditioning ◽  
Humoral Factors

Remote ischemic preconditioning (RIPC) protects hearts from ischemia–reperfusion (I/R) injury in experimental studies; however, clinical RIPC trials were unsatisfactory. This discrepancy could be caused by a loss of cardioprotection due to comorbidities in patients, including diabetes mellitus (DM) and hyperglycemia (HG). RIPC is discussed to confer protective properties by release of different humoral factors activating cardioprotective signaling cascades. Therefore, we investigated whether DM type 1 and/or HG (1) inhibit the release of humoral factors after RIPC and/or (2) block the cardioprotective effect directly at the myocardium. Experiments were performed on male Wistar rats. Animals in part 1 of the study were either healthy normoglycemic (NG), type 1 diabetic (DM1), or hyperglycemic (HG). RIPC was implemented by four cycles of 5 min bilateral hind-limb ischemia/reperfusion. Control (Con) animals were not treated. Blood plasma taken in vivo was further investigated in isolated rat hearts in vitro. Plasma from diseased animals (DM1 or HG) was administered onto healthy (NG) hearts for 10 min before 33 min of global ischemia and 60 min of reperfusion. Part 2 of the study was performed vice versa—plasma taken in vivo, with or without RIPC, from healthy rats was transferred to DM1 and HG hearts in vitro. Infarct size was determined by TTC staining. Part 1: RIPC plasma from NG (NG Con: 49 ± 8% vs. NG RIPC 29 ± 6%; p < 0.05) and DM1 animals (DM1 Con: 47 ± 7% vs. DM1 RIPC: 38 ± 7%; p < 0.05) reduced infarct size. Interestingly, transfer of HG plasma showed comparable infarct sizes independent of prior treatment (HG Con: 34 ± 9% vs. HG RIPC 35 ± 9%; ns). Part 2: No infarct size reduction was detectable when transferring RIPC plasma from healthy rats to DM1 (DM1 Con: 54 ± 13% vs. DM1 RIPC 53 ± 10%; ns) or HG hearts (HG Con: 60 ± 16% vs. HG RIPC 53 ± 14%; ns). These results suggest that: (1) RIPC under NG and DM1 induces the release of humoral factors with cardioprotective impact, (2) HG plasma might own cardioprotective properties, and (3) RIPC does not confer cardioprotection in DM1 and HG myocardium.

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