OBJECTIVEA general review was made of studies involving: (1) The experimental evidence of remote ischemic preconditioning (RIPC) and relative clinical studies, (2) The experimental and clinical evidences of remote ischemic postconditioning (RIPOC), (3) The potential mechanistic pathways underlying their protective effects.

DATA SOURCESThe data used in this review were mainly from manuscripts listed in PubMed that were published in English from 1986 to 2010. The search terms were "myocardial ischemia reperfusion injury", "ischemia preconditioning", "ischemia postconditioning", "remote preconditioning" and "remote postconditioning".

STUDY SELECTION(1) Clinical and experimental evidence that both RIPC and RIPOC produce preservation of ischemia reperfusion injury (IRI) of myocardium and other organs, (2) Studies related to the potential mechanisms, by which remote ischemic conditioning protects myocardium against IRI.

RESULTSBoth RIPC and RIOPC have been shown to attenuate myocardial IRI in laboratory animals. Also, their cardioprotective effects have appeared in some clinical studies. Except the external, the detailed internal mechanisms of remote ischemic conditioning have been generally described. Through these descriptions better protocols can be developed to provide improved cardioprotective procedures.

CONCLUSIONSRemote ischemic conditioning is an endogenous cardioprotective mechanism from outside the heart that protects against myocardial IRI and represents a general form of inter-organ protection. Remote ischemic conditioning may have an immense impact on clinical practice in the near future.

Humans ; Ischemic Preconditioning, Myocardial ; methods ; Myocardial Reperfusion Injury ; prevention & control

This study observed the protective effect of hypercapnic acidosis preconditioning on rabbit heart suffered from ischemia-reperfusion injury. Hypercapnic acidosis was established in animals with mechanical hypoventilation before ischemia-reperfusion. Thirty-two rabbits were randomly divided into 4 groups, with each having 8 animals in term of the degree of acidification: hypercapnic acidosis group A (group A), hypercapnic acidosis group B (group B), hypercapnic acidosis group C (group C), ischemia and reperfusion group (group IR). Animals in group IR were ventilated normally (tidal volume: 15 mL/kg, breathing rate 35 bpm). The PETCO(2) was maintained at the level of 40-50 mmHg for 30 min. Animals in groups A, B, C received low-frequency, low-volume ventilation to achieve hypercarbonic acidosis and the target levels of PETCO(2) were 75-85,65-75, 55-65 mmHg, respectively, with levels being maintained for 5 min. The animals then were ventilated normally to lower PETCO(2) to 40-50 mmHg. The left anterior branch artery of all the animals was ligated for 30 min and reperfused for 180 min. Then the infarct size was calculated. The cardiomyocytes were morphologically observed and ECG and hemodynamics were monitored on continuous basis. Acid-base balance was measured during procedure. Our results showed that the infarct size was (48.5+/-11.5)% of the risk area in the control group and (42.4+/-7.9)% in group C (P>0.05). Mean infarct size was significantly smaller in group B (34.5%+/-9.4%) (P<0.05 vs control group) and group A (31.0%+/-9.1%) (P<0.01 vs control group). It is concluded that HA-preconditioning can effectively protect the myocardium.
Acidosis, Respiratory/*physiopathology ; Hypercapnia/*physiopathology ; Ischemic Preconditioning, Myocardial/*methods ; Myocardial Reperfusion Injury/*prevention & control ; Random Allocation

Animals ; Disease Models, Animal ; Ischemic Preconditioning, Myocardial ; methods ; Myocardial Reperfusion Injury ; prevention & control ; Rats ; Rats, Wistar

Female ; Humans ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Myocardial Reperfusion Injury ; prevention & control

Animals ; Humans ; Ischemic Preconditioning, Myocardial ; methods ; Myocardial Ischemia ; complications ; therapy ; Myocardial Reperfusion ; methods ; Myocardial Reperfusion Injury ; etiology ; prevention & control

The concept of "ischemic postconditioning" was first raised in 2002, and the following 5 year research shows that it can protect organs from reperfusion injury. Although the mechanism of ischemic postconditioning is similar to ischemic preconditioning in many ways, it still has its own characteristics. Reperfusion injury is an inevitable problem in organ transplantation. It may accelerate the function recovery of the transplants to lessen the reperfusion injury. So ischemic postconditioning may have a fine prospect in organ transplantation for its good controllability during reperfusion. This article is going to briefly introduce the distinct mechanisms of ischemic postconditioning to protect organs from reperfusion injury and approach the possibilities of its application in organ transplantation.
Animals ; Humans ; Ischemic Preconditioning ; Ischemic Preconditioning, Myocardial ; Myocardial Reperfusion Injury ; pathology ; prevention & control ; Organ Transplantation ; adverse effects ; methods ; Reperfusion Injury ; prevention & control

AIMTo investigate the protective effects and mechanism of IPC on myocardial ischemia/reperfusion injury.

METHODSEffects of IPC on arrhythmia and coronary blood flow and the release of AST, CPK, LDH, SOD and LFO at different time after ischemia/reperfusion injury in rat Langendorff hearts were studied.

RESULTSIPC decreased the release of AST, CPK and LDH and increased myocardial SOD activity and decreased LPO level. IPC also inhibited ischemia/reperfusion arrhythmias and increased coronary blood flow.

CONCLUSIONThe results showed that IPC had well protective effects on myocardial ischemia/reperfusion injury.

Animals ; Female ; Heart ; physiopathology ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Myocardial Reperfusion Injury ; prevention & control ; Rats ; Rats, Wistar

This study examined the protective effect of ischemic postconditioning (IPoC) and minocycline postconditioning (MT) on myocardial ischemia-reperfusion (I/R) injury in atherosclerosis (AS) animals and the possible mechanism. Forty male healthy rabbits were injected with bovine serum albumin following feeding on a high fat diet for 6 weeks to establish AS model. AS rabbits were randomly divided into 3 groups: (1) I/R group, the rabbits were subjected to myocardial ischemia for 35 min and then reperfusion for 12 h; (2) IPoC group, the myocardial ischemia lasted for 35 min, and then reperfusion for 20 s and ischemia for 20 s [a total of 3 cycles (R20s/I20s×3)], and then reperfusion was sustained for 12 h; (3) MT group, minocycline was intravenously injected 10 min before reperfusion. The blood lipids, malondialdehyde (MDA), superoxide dismutase (SOD), soluble cell adhesion molecule (sICAM), myeloperoxidase (MPO), and cardiac troponin T (cTnT) were biochemically determined. The myocardial infarction size (IS) and apoptosis index (AI) were measured by pathological examination. The expression of bcl-2 and caspase-3 was detected in the myocardial tissue by using reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the AS models were successfully established. The myocardial IS, the plasma levels of MDA, sICAM, MPO and cTnT, and the enzymatic activity of MPO were significantly decreased, and the plasma SOD activity was significantly increased in IPoC group and MT group as compared with I/R group (P<0.05 for all). The myocardial AI and the caspase-3 mRNA expression were lower and the bcl-2 mRNA expression was higher in IPoC and MT groups than those in I/R group (all P<0.05). It is concluded that the IPoC and MT can effectively reduce the I/R injury in the AS rabbits, and the mechanisms involved anti-oxidation, anti-inflammation, up-regulation of bcl-2 expression and down-regulation of caspase-3 expression. Minocycline can be used as an effective pharmacologic postconditioning drug to protect myocardia from I/R injury.
Animals ; Atherosclerosis ; physiopathology ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Minocycline ; pharmacology ; Myocardial Reperfusion Injury ; physiopathology ; Rabbits ; Reperfusion Injury ; physiopathology

BACKGROUNDPostconditioning has been shown to reduce infarct size, ischemic/reperfusion injury and myocardial injury in patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI). This study tested the hypothesis that postconditioning attenuates the elevation of tumor necrosis factor-alpha (TNF-alpha) and improves heart function in patients with AMI after PCI.

METHODSA total of 75 patients were randomly assigned to 1 of 3 groups: the routine group (n = 26), in which no intervention was given at the onset of reperfusion; and the Postcon-30s (n = 25) or Postcon-60 s (n = 24) groups, in which 3 cycles of 30- or 60-second balloon deflation and inflation were repetitively performed. TNF-alpha serum concentration was measured by ELISA. Global and regional left ventricular systolic function was determined by echocardiography at 1 year. Thirty-four normal controls (NC) were enrolled in the study.

RESULTSThe TNF-alpha concentration in patients with AMI was significantly elevated at baseline compared to controls (P < 0.01). Concentration levels increased in the routine and Postcon-30s, but not in Postcon-60s group at 7 days (P < 0.05). As for linear associations among the three groups, left ventricular ejection fraction (LVEF) and wall motion score index (WMSI) were ranked as follows: Postcon-60s > Postcon-30s > routine (P values all < 0.05, 65% vs. 57% vs. 52% and 1.10 vs. 1.27 vs. 1.53) after 1 year. More importantly, there was a significant relevance between the soluble TNF-alpha serum concentration at 7 days and LVEF or WMSI after 1 year (P values all < 0.0001).

CONCLUSIONSPostconditioning, in particular Postcon-60s was associated with long-term cardioprotective effects for inhibition of the inflammatory response and reperfusion injury. The soluble TNF-alpha serum concentration provided powerful prognostic information of global and regional left ventricular systolic function in patients with AMI.

Angioplasty, Balloon, Coronary ; methods ; Female ; Humans ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Middle Aged ; Myocardial Infarction ; therapy ; Myocardial Reperfusion Injury ; prevention & control ; Tumor Necrosis Factor-alpha ; blood

BACKGROUNDPlasma transfusion is a common clinical practice. Remote ischemic preconditioning (RIPC) protects organs against ischemia-reperfusion (IR) injury. Whether preconditioned plasma (PP), collected at late phase after RIPC, could protect organs against IR injury in vivo is unknown. This study explored whether transfusion of PP could reduce myocardial infarct size (IS) after IR in rat in vivo.

METHODSEighty Lewis rats were randomized to eight groups (n = 10 for each group). Two groups of plasma donor rats donated plasma at 48 h after transient limb ischemia (PP) or control protocol (nonpreconditioned plasma [NPP]). Six groups of recipient rats received normal saline (NS; NS-IR 1, and NS-IR 24 groups), NPP (NPP-IR 1 and NPP-IR 24 groups), or PP (PP-IR 1 and PP-IR 24 groups) at one or 24 h before myocardial IR. Myocardial IR consisted of 30-min left anterior descending (LAD) coronary artery occlusion and 180-min reperfusion. The area at risk (AAR) and infarct area were determined by double-staining with Evans blue and triphenyltetrazolium chloride. IS was calculated by infarct area divided by AAR. This was a 3 × 2 factorial design study, and factorial analysis was used to evaluate the data. If an interaction between the fluid and transfusion time existed, one-way analysis of variance with Bonferroni correction for multiple comparisons was used to analyze the single effects of fluid type when the transfusion time was fixed.

RESULTSIS in the NPP-IR 1 and PP-IR 1 groups was smaller than in the NS-IR 1 group (F = 6.838, P = 0.005; NPP-IR 1: 57 ± 8% vs. NS-IR1: 68 ± 6%, t = 2.843, P = 0.020; PP-IR 1: 56 ± 8% vs. NS-IR 1: 68 ± 6%, t = 3.102, P = 0.009), but no significant difference was detected between the NPP-IR 1 and PP-IR 1 groups (57 ± 8% vs. 56 ± 8%, t = 0.069, P = 1.000). IS in the NPP-IR 24 and PP-IR 24 groups was smaller than in the NS-IR 24 group (F = 24.796, P< 0.001; NPP-IR 24: 56% ± 7% vs. NS-IR 24: 68 ± 7%, t = 3.102, P = 0.026; PP-IR 24: 40 ± 9% vs. NS-IR 24: 68 ± 7%, t = 7.237, P< 0.001); IS in the PP-IR 24 group was smaller than in the NPP-IR 24 group (40 ± 9% vs. 56 ± 7%, t = 4.135, P = 0.002).

CONCLUSIONTransfusion of PP collected at late phase after remote ischemic preconditioning could reduce IS, suggesting that late-phase cardioprotection was transferable in vivo.

Animals ; Blood Component Transfusion ; methods ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Myocardial Infarction ; etiology ; prevention & control ; Myocardial Reperfusion Injury ; complications ; Plasma ; Rats