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

OBJECTIVETo study the protective effect of sufentanil preconditioning against myocardial ischemia-reperfusion (I/R) injury and the role of PI3K/Akt signaling pathway.

METHODSSixty male SD rats weighing 250-350 g were randomly divided into 5 equal groups, namely the sham-operated group, I/R group, sufentanil preconditioning group (Spc group), sufentanil preconditioning +PI3K inhibitor group (Spc+W group), and PI3K inhibitor group (W group). Myocardial I/R model was established by ligation of the anterior descending branch of the left coronary artery for 30 min followed by reperfusion for 120 min. Sufentanil was administered in 3 doses via the femoral vein before the occlusion, each at 1 µg/kg infused within 5 min at a 5-min interval. In Spc+W and W groups, PI3K inhibitor wortmannin (15 µg/kg) was given intravenously 5 min before sufentanil preconditioning and 35 min before ischemia, respectively. Heart rate and mean arterial pressure (MAP) were continuously monitored during I/R. At the end of reperfusion, blood samples were obtained to determine plasma activation of CK-MB and LDH. Acute infarct size was measured by triphenyltetrazolium chloride staining, and the myocardial tissues were obtained to detect the expression of phosphorylated Akt using Western blotting.

RESULTSPhosphorylated Akt expression was significantly up-regulated in I/R and Spc groups as compared with the sham group, and was significantly higher in Spc group than in I/R group. After reperfusion, sufentanil preconditioning significantly decreased myocardial infarct size (P<0.01) and lowered the levels of CK-MB (P<0.01) and LDH (P<0.01) compared with those in the I/R group. The I/R , Spc+W and W groups showed no significant differences in myocardial infarct size or the levels of CK-MB and LDH.

CONCLUSIONThe protective effect of sufentanil preconditioning against myocardium against I/R injury in rats may involve PI3K/Akt signaling pathway activation.

Animals ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Myocardial Reperfusion Injury ; metabolism ; prevention & control ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Signal Transduction ; Sufentanil ; pharmacology

OBJECTIVETo observe the protective effect of Wufu Jingfang (WJ, containing Aconitum carmichaeli Debx, Radix Aconiti Lateralis Preparatae, Rhizoma Pinelliae, and snakegourd fruit) on myocardial ischemia-reperfusion injury (I/R) of rats, thus exploring the feasibility of recipes containing eighteen incompatible pairs for specific pathological conditions.

METHODSFifty male Wistar rats were randomly divided into five groups, i.e., the sham-operative control group (the SH group), the I/R group, the low dose WJ I/R group (the I/R +JFL group), the middle dose WJ I/R group (the I/R +JFM group), the high dose WJ I/R group (the I/R +JFH group), 10 in each group. Rats in the latter three groups were administered with WJ at 0.75 mL/100 g, 1.50 mL/100 g, and 3.00 mL/100 g body weight for 14 consecutive days by gastrogavage. All groups except the SH group received ligation of left anterior descending branch of coronary artery for 30-min ischemia followed by 120-min reperfusion. The micro-structural changes of myocardial mitochondria were observed by transmission electron microscope. The ischemic cardiomyocyte apoptosis was detected in each group using one-step terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL). The mRNA expressions of B-cell leukemia/lymphoma 2 (Bcl-2) and Bcl-2 associated x protein (Bax) were detected by RT-PCR. The activities of lactic dehydrogenase (LDH) and creatine kinase (CK) were detected using ELISA. The myocardial infarct size was detected.

RESULTSCompared with the I/R group, WJ pretreatment significantly suppressed the release of LDH and CK (Besides, the release of LDH and CK reduced along with increased dose.), reduced the myocardial infarct size, and lowered myocardial apoptosis index (P < 0.05). WJ pretreatment also modulated Bcl-2/Bax ratio by up-regulating Bcl-2 expression level while decreasing Bax expression level.

CONCLUSIONSWJ pretreatment might protect the heart from I/R injury via decreasing myocardial cell apoptosis. The results suggested that eighteen incompatible pairs is not absolute, but relative. Chinese medical preparation containing opposite Chinese herbs could be used in specific pathological states such as ischemic cardiomyopathy.

Animals ; Apoptosis ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Myocardial Reperfusion Injury ; pathology ; Rats ; Rats, Wistar

BACKGROUNDBoth ischemic preconditioning (IPC) and limb remote ischemic postconditioning (LRIPOC) have been shown to possess significantly different cardioprotective effects against the myocardial ischemia reperfusion injury (IRI), but no study has compared the anti-inflammatory effects of IPC and LRIPOC during myocardial IRI process. We hypothesized that IPC and LRIPOC would produce different anti-inflammatory effects in an in vivo rat model with myocardial IRI.

METHODSEighty rats were randomly allocated into four equal groups: sham group, IRI group, IPC group and LRIPOC group. In 10 rats randomly selected from each group, serum levels of TNF-α, HMGB1, ICAM1, IL-1, IL-6 and IL-10 were assessed, and infarct size was determined. In another 10 rats of each group, myocardial levels of TNF-α, HMGB1, ICAM1, IL-1, IL-6 and IL-10 in both ischemic and non-ischemic regions were measured.

RESULTSThe infarct size was significantly lower in IPC and LRIPOC groups than in IRI group. The serum and myocardial levels of pro-inflammatory cytokines including TNF-α, HMGB1, ICAM1, IL-1 and IL-6 during reperfusion were significantly reduced in IPC and LRIPOC groups compared to IRI group. As compared to the IPC group, infarct size, serum level of TNF-α at 60 minutes of reperfusion, serum levels of HMGB1 and ICAM1 at 120 minutes of reperfusion, myocardial levels of TNF-α, ICAM1, IL-1 and IL-6 in the ischemic region, myocardial levels of ICAM1, IL-1 and IL-6 in the non-ischemic region were significantly increased in the LRIPOC group.

CONCLUSIONSIn the rats with myocardial IRI, IPC produces more powerful inhibitory effects on local myocardial and systemic inflammatory responses than LRIPOC. This may be partly attributed to more potent cardioprotection produced by IPC.

Animals ; HMGB1 Protein ; metabolism ; Intercellular Adhesion Molecule-1 ; metabolism ; Interleukin-1 ; metabolism ; Interleukin-10 ; metabolism ; Interleukin-6 ; metabolism ; Ischemic Postconditioning ; methods ; Ischemic Preconditioning ; methods ; Male ; Myocardial Reperfusion Injury ; immunology ; metabolism ; therapy ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha ; metabolism

Animals ; Drugs, Chinese Herbal ; administration & dosage ; therapeutic use ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Myocardial Ischemia ; prevention & control ; Myocardial Reperfusion Injury ; prevention & control ; Rabbits

Myocardial ischemic preconditioning and postconditioning can reduce myocardial infarct size, improve myocardial contractility, protect coronary endothelial and myocardial cell ultrastructure, as well as reduce the incidence of arrhythmias. Clinical practice has confirmed the safety and efficacy of these two methods of myocardial protection. This paper reviewed about ischemic preconditioning and postconditioning protection mechanisms in myocardial ischemia reperfusion injury and clinical research literatures in recent years, to provide a theoretical basis for finding new treatment strategies on the prevention and treatment of ischemic cardiomyopathy.
Animals ; Humans ; Ischemic Postconditioning ; methods ; Ischemic Preconditioning, Myocardial ; methods ; Myocardial Infarction ; therapy ; Myocardial Ischemia ; therapy ; Myocardial Reperfusion ; adverse effects ; Myocardial Reperfusion Injury ; etiology ; prevention & control ; Receptors, G-Protein-Coupled ; agonists ; Signal Transduction

BACKGROUNDInflammation is one of important mechanisms for myocardial ischemia reperfusion injury (IRI). Ischemia postconditioning (IPOC) can protect the heart against IRI by inhibiting inflammation, but its cardioprotection is weaker than that of ischemia preconditioning. Recently, the α7 subunit-containing nicotinic acetylcholine receptor (α7nAChR) agonist has shown anti-inflammatory effects in many diseases related to inflammation. This randomized controlled experiment was designed to evaluate whether combined postconditioning with IPOC and the α7nAChR agonist could produce an enhanced cardioprotection in a rat in vivo model of acute myocardial IRI.

METHODSFifty Sprague-Dawley rats were randomly divided into five equal groups: sham group, control group, IPOC group, α7nAChR agonist postconditioning group (APOC group) and combined postconditioning with IPOC and α7nAChR agonist group (combined group). Hemodynamic parameters were recorded during the periods of ischemia and reperfusion. Serum concentrations of troponin I (TnI), tumor necrosis factor α (TNF-α) and high-mobility group box 1 (HMGB-1) at 180 minutes after reperfusion were assayed in all groups. At the end of the experiment, the infarct size was assessed from excised hearts by Evans blue and triphenyl tetrazolium chloride staining.

RESULTSAs compared to the sham group, the infarct size in the other four groups was significantly increased, serum levels of TnI, TNF-α and HMGB1 in the control group and TNF-α, HMGB1 in the IPOC group were significantly increased. The infarct size and serum concentrations of TNF-α, HMGB1 and TnI in the IPOC, APOC and combined groups were significantly lower than those in the control group. As compared to the IPOC group, the infarct size in the combined group was significantly decreased, serum concentrations of TnI, TNF-α and HMGB1 in the APOC and combined groups were significantly reduced. Although the infarct size was significantly smaller in the combined group than in the APOC group, serum levels of TNF-α and HMGB1 were significantly higher in the combined group than in the APOC group.

CONCLUSIONSIn a rat in vivo model of acute myocardial IRI, combined postconditioning with IPOC and the α7nAChR agonist can produce enhanced protection against myocardial IRI by increasing the anti-inflammatory effect.

Animals ; Heart ; drug effects ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Myocardial Reperfusion Injury ; prevention & control ; Myocardium ; pathology ; Nicotinic Agonists ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Receptors, Nicotinic ; metabolism ; Tumor Necrosis Factor-alpha ; blood ; alpha7 Nicotinic Acetylcholine Receptor

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

OBJECTIVETo investigate the role of connexin 43-formed hemichannels in cell volume regulation induced by simulated ischemia/reperfusion (SI/R).

METHODSMouse cardiomyocytes isolated on a Langendorff apparatus with enzyme solution were aliquoted into control, SI/R and SI/R +octanol groups. Calcein-AM was used to stain the cells and the cell volume was measured with confocal microscope by stack scanning. Trypan blue was used to measure the cell viability after the treatments.

RESULTSCalcein-AM staining and cofocal microscopy yielded stable and reproducible results for cell volume measurement. Mouse cardiomyocytes subjected to simulated SI/R showed obvious cell swelling as compared with the control cells [(126∓6)% vs 100%, P<0.05], and octanol preconditioning significantly attenuated the cell swelling [(113∓6)%, P<0.05]. SI/R caused a significant reduction of the cell viability compared to the control cells [(19∓2)% vs (45∓3)%, P<0.01], and octanol preconditioning obviously reduced the viability of the cells with SI/R challenge [(31∓2)%, P<0.01].

CONCLUSIONConnexin 43-formed hemichannels are involved in the regulation of cardiomyocyte volumes induced by SI/R challenge, and octanol can alleviate the cell swelling to enhance the viability of the cardiomyocytes following SI/R.

Animals ; Cell Line ; Cell Size ; Cell Survival ; Connexin 43 ; metabolism ; Ischemic Preconditioning, Myocardial ; methods ; Mice ; Mice, Inbred C57BL ; Myocardial Reperfusion Injury ; metabolism ; pathology ; Myocytes, Cardiac ; drug effects ; pathology ; Octanols ; pharmacology

OBJECTIVE: To determine the effect of Gingkgo biloba leaf extract (EGb761) induced delayed preconditioning on cytochrome c oxidase (CcO) expression during myocardial ischemia-reperfusion in rats. METHODS: Four groups (10 in each) of Sprague-Dawley male rats were studied. In the sham group, the rats received no treatment. Rats in the ischemia-reperfusion (IR) group were treated with NS (1.0 mL/kg intravenously) 24 h before ischemia. Rats in the M group were treated with EGb761 (100 mg/kg intravenously) 24 h before the ischemia. In the D group , EGb761-treated rats that received the 5-hydroxydecanoate (5-HD), an inhibitor of mitochondrial KATP channels 15 min before the ischemia. The IR, M, and D groups were subjected to ischemia by 30 min of coronary artery occlusion before 2 h of reperfusion. At the end of the reperfusion, myocardial infarct size was measured. CcO was measured by Western blot. The myocardial ultrastructure was observed under the electron microscope. RESULTS: The infarct size was significantly smaller in the M group [(23.78 ± 4.82)%] than in the I/R group [(37.87 ± 5.92)%] (P<0.05). The CcO protein expression in the myocardium was significantly higher in the M group than in the I/R group(P<0.05). Microscopic examination showed less myocardial damage in the M group than that in the I/R group. The infarct size, CcO protein expression, and myocardial damage had no significant difference between the D group and the I/R group (P>0.05). CONCLUSION EGb761 induced delayed preconditioning attenuates myocardial ischemia-reperfusion injury possibly through up-regulating CcO expression in rats.
Animals ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Electron Transport Complex IV ; metabolism ; Ginkgo biloba ; chemistry ; Ischemic Postconditioning ; methods ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Myocardial Ischemia ; physiopathology ; Myocardial Reperfusion Injury ; metabolism ; prevention & control ; Phytotherapy ; Plant Leaves ; chemistry ; Rats ; Rats, Sprague-Dawley