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1.  Activation of Akt and cardioprotection against reperfusion injury are maximal with only five minutes of sevoflurane postconditioning in isolated rat hearts*  
It had been proved that administration of sevoflurane for the first two minutes of reperfusion effectively protects the heart against reperfusion injury in rats in vivo. Our aim was to investigate the duration of effective sevoflurane administration and its underlying mechanism in isolated rat hearts exposed to global ischemia/reperfusion (I/R) injury. Adult male Sprague-Dawley rats were randomly divided into six groups (n=12): a sham-operation group, an I/R group, and four sevoflurane postconditioning groups (S2, S5, S10, and S15). In the S2, S5, S10, and S15 groups, the duration times of sevoflurane administration were 2, 5, 10, and 15 min after the onset of reperfusion, respectively. The isolated rat hearts were mounted on the Langendorff system, and after a period of equilibrium were subjected to 40 min global ischemia and 120 min reperfusion. Left ventricular (LV) hemodynamic parameters were monitored throughout each experiment and the data at 30 min of equilibrium and 30, 60, 90, and 120 min of reperfusion were analyzed. Myocardial infarct size at the end of reperfusion (n=7 in each group) and the expression of myocardial phosphorylated Akt (p-Akt) after 15-min reperfusion were determined in a duplicate set of six groups of rat hearts (n=5 in each group). Compared with the I/R group, the S5, S10, and S15 groups had significantly improved left ventricular end-diastolic pressure (LVEDP), left ventricular developed pressure (LVDP), and the maximal rate of rise or fall of the LV pressure (±dP/dt max), and decreased myocardial infarct size (P<0.05), but not the S2 group. After 15 min of reperfusion, the expression of p-Akt was markedly up-regulated in the S5, S10, and S15 groups compared with that in the I/R group (P<0.05), but not in the S2 group. Sevoflurane postconditioning for 5 min was sufficient to activate Akt and exert maximal cardioprotection against I/R injury in isolated rat hearts.
doi:10.1631/jzus.B1200195
PMCID: PMC3682167  PMID: 23733428
Sevoflurane postconditioning; Ischemia/reperfusion (I/R) injury; Cardioprotection; Duration of administration; Akt
2.  PI3K Contributed to Modulation of Spinal Nociceptive Information Related to ephrinBs/EphBs 
PLoS ONE  2012;7(8):e40930.
There is accumulating evidence to implicate the importance of EphBs receptors and ephrinBs ligands were involved in modulation of spinal nociceptive information. However, the downstream mechanisms that control this process are not well understood. In the present study, we investigated whether phosphatidylinositol 3-kinase (PI3K), as the downstream effectors, participates in modulation of spinal nociceptive information related to ephrinBs/EphBs. Intrathecal injection of ephrinB1-Fc produced a dose- and time-dependent thermal and mechanical hyperalgesia, accompanied by the increase of spinal PI3K-p110γ, phosphorylation of AKT (p-AKT) and c-Fos expression. Pre-treatment with PI3K inhibitor wortmannin or LY294002 prevented activation of spinal AKT induced by ephrinB1-Fc. Inhibition of spinal PI3K signaling dose-dependently prevented and reversed pain behaviors and spinal c-Fos protein expression induced by intrathecal injection of ephrinB1-Fc. Inhibition of EphBs receptors by intrathecal injection of EphB1-Fc reduced formalin-induced inflammation and chronic constrictive injury-induced neuropathic pain behaviors accompanied by decreased expression of spinal PI3K,p-AKT and c-Fos protein. Furthermore, pre-treatment with PI3K inhibitor wortmannin or LY294002 prevented ephrinB1-Fc-induced ERK activation in spinal. These data demonstrated that PI3K and PI3K crosstalk to ERK signaling contributed to modulation of spinal nociceptive information related to ephrinBs/EphBs.
doi:10.1371/journal.pone.0040930
PMCID: PMC3411731  PMID: 22879882
3.  Sevoflurane postconditioning reduces myocardial reperfusion injury in rat isolated hearts via activation of PI3K/Akt signaling and modulation of Bcl-2 family proteins*  
Sevoflurane postconditioning reduces myocardial infarct size. The objective of this study was to examine the role of the phosphatidylinositol-3-kinase (PI3K)/Akt pathway in anesthetic postconditioning and to determine whether PI3K/Akt signaling modulates the expression of pro- and antiapoptotic proteins in sevoflurane postconditioning. Isolated and perfused rat hearts were prepared first, and then randomly assigned to the following groups: Sham-operation (Sham), ischemia/reperfusion (Con), sevoflurane postconditioning (SPC), Sham plus 100 nmol/L wortmannin (Sham+Wort), Con+Wort, SPC+Wort, and Con+dimethylsulphoxide (DMSO). Sevoflurane postconditioning was induced by administration of sevoflurane (2.5%, v/v) for 10 min from the onset of reperfusion. Left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), maximum increase in rate of LVDP (+dP/dt), maximum decrease in rate of LVDP (−dP/dt), heart rate (HR), and coronary flow (CF) were measured at baseline, R30 min (30 min of reperfusion), R60 min, R90 min, and R120 min. Creatine kinase (CK) and lactate dehydrogenase (LDH) were measured after 5 min and 10 min reperfusion. Infarct size was determined by triphenyltetrazolium chloride staining at the end of reperfusion. Total Akt and phosphorylated Akt (phospho-Akt), Bax, Bcl-2, Bad, and phospho-Bad were determined by Western blot analysis. Analysis of variance (ANOVA) and Student-Newman-Keuls’ test were used to investigate the significance of differences between groups. The LVDP, ±dP/dt, and CF were higher and LVEDP was lower in the SPC group than in the Con group at all points of reperfusion (P<0.05). The SPC group had significantly reduced CK and LDH release and decreased infarct size compared with the Con group [(22.9±8)% vs. (42.4±9.4)%, respectively; P<0.05]. The SPC group also had increased the expression of phosphor-Akt, Bcl-2, and phospho-Bad, and decreased the expression of Bax. Wortmannin abolished the cardioprotection of sevoflurane postconditioning. Sevoflurane postconditioning may protect the isolated rat heart. Activation of PI3K and modulation of the expression of pro- and antiapoptotic proteins may play an important role in sevoflurane-induced myocardial protection.
doi:10.1631/jzus.B1000155
PMCID: PMC2932876  PMID: 20803770
Sevoflurane; Postconditioning; Cardioprotection; Akt; Bcl-2; Bad
4.  Effects of sevoflurane preconditioning and postconditioning on rat myocardial stunning in ischemic reperfusion injury*  
Ischemic preconditioning and postconditioning distinctly attenuate ventricular arrhythmia after ischemia without affecting the severity of myocardial stunning. Therefore, we report the effects of sevoflurane preconditioning and postconditioning on stunned myocardium in isolated rat hearts. Isolated rat hearts were underwent 20 min of global ischemia and 40 min of reperfusion. After an equilibration period (20 min), the hearts in the preconditioning group were exposed to sevoflurane for 5 min and next washout for 5 min before ischemia. Hearts in the sevoflurane postconditioning group underwent equilibration and ischemia, followed immediately by sevoflurane exposure for the first 5 min of reperfusion. The control group received no treatment before and after ischemia. Left ventricular pressure, heart rate, coronary flow, electrocardiogram, and tissue histology were measured as variables of ventricular function and cellular injury, respectively. There was no significant difference in the duration of reperfusion ventricular arrhythmias between control and sevoflurane preconditioning group (P=0.195). The duration of reperfusion ventricular arrhythmias in the sevoflurane postconditioning group was significantly shorter than that in the other two groups (P<0.05). ±(dP/dt)max in the sevoflurane preconditioning group at 5, 10, 15, 20, and 30 min after reperfusion was significantly higher than that in the control group (P<0.05), and there were no significant differences at 40 min after reperfusion among the three groups (P>0.05). As expected, for a 20-min general ischemia, infarct size in heart slices determined by 2,3,5-triphenyltetrazolium chloride staining among the groups was not obvious. Sevoflurane postconditioning reduces reperfusion arrhythmias without affecting the severity of myocardial stunning. In contrast, sevoflurane preconditioning has no beneficial effects on reperfusion arrhythmias, but it is in favor of improving ventricular function and recovering myocardial stunning. Sevoflurane preconditioning and postconditioning may be useful for correcting the stunned myocardium.
doi:10.1631/jzus.B0900390
PMCID: PMC2852543  PMID: 20349523
Inhalation anesthetics; Sevoflurane; Postconditioning; Preconditioning; Ischemia-reperfusion injury; Myocardial stunning
5.  Postconditioning of sevoflurane and propofol is associated with mitochondrial permeability transition pore*  
Background: Sevoflurane and propofol are effective cardioprotective anaesthetic agents, though the cardioprotection of propofol has not been shown in humans. Their roles and underlying mechanisms in anesthetic postconditioning are unclear. Mitochondrial permeability transition pore (MPTP) opening is a major cause of ischemia-reperfusion injury. Here we investigated sevoflurane- and propofol-induced postconditioning and their relationship with MPTP. Methods: Isolated perfused rat hearts were exposed to 40 min of ischemia followed by 1 h of reperfusion. During the first 15 min of reperfusion, hearts were treated with either control buffer (CTRL group) or buffer containing 20 µmol/L atractyloside (ATR group), 3% (v/v) sevoflurane (SPC group), 50 µmol/L propofol (PPC group), or the combination of atractyloside with respective anesthetics (SPC+ATR and PPC+ATR groups). Infarct size was determined by dividing the total necrotic area of the left ventricle by the total left ventricular slice area (percent necrotic area). Results: Hearts treated with sevoflurane or propofol showed significantly better recovery of coronary flow, end-diastolic pressures, left ventricular developed pressure and derivatives compared with controls. Sevoflurane resulted in more protective alteration of hemodynamics at most time point of reperfusion than propofol. These improvements were paralleled with the reduction of lactate dehydrogenase release and the decrease of infarct size (SPC vs CTRL: (17.48±2.70)% vs (48.47±6.03)%, P<0.05; PPC vs CTRL: (35.60±2.10)% vs (48.47±6.03)%, P<0.05). SPC group had less infarct size than PPC group (SPC vs PPC: (17.48±2.70)% vs (35.60±2.10)%, P<0.05). Atractyloside coadministration attenuated or completely blocked the cardioprotective effect of postconditioning of sevoflurane and propofol. Conclusion: Postconditioning of sevoflurane and propofol has cardioprotective effect against ischemia-reperfusion injury of heart, which is associated with inhibition of MPTP opening. Compared to propofol, sevoflurane provides superior protection of functional recovery and infarct size.
doi:10.1631/jzus.B0710586
PMCID: PMC2225491  PMID: 18257131
Sevoflurane; Propofol; Postconditioning; Reperfusion injury; Mitochondrial permeability transition pore (MPTP)
6.  Effect of perioperative autologous versus allogeneic blood transfusion on the immune system in gastric cancer patients*  
Background: Allogeneic blood transfusion-induced immunomodulation (TRIM) and its adverse effect on the prognosis of patients treated surgically for cancer remain complex and controversial. However, the potential risk associated with allogeneic blood transfusion has heightened interest in the use of autologous blood transfusion. In the present study, the serum concentrations of neopterin, interferon-gamma (IFN-γ), T lymphocyte subsets (CD3+, CD4+, CD8+, CD4+/CD8+) and a possible association between these variables were investigated. The purpose was to further evaluate the effect of autologous versus allogeneic blood transfusion on immunological status in patients undergoing surgery for gastric cancer. Methods: Sixty ASA I~II (American Society of Anesthesiologists) patients undergoing elective radical resection for stomach cancer were randomly allocated to receive either allogeneic blood transfusion (n=30) or autologous blood transfusion (n=30). Serum concentrations of the neopterin, IFN-γ and T lymphocyte subsets in the recipients were measured before induction of anesthesia, after operation, and on the 5th postoperative day. Results: Both two groups, serum neopterin, IFN-γ, percentages of T-cell subsets (CD3+, CD4+), and CD4+/CD8+ ratio had significantly decreased after operation, but decreased more significantly in group H (receiving allogeneic blood transfusion) than those in group A (receiving autologous whole blood transfusion) (P<0.05). On the 5th postoperative day, serum neopterin, IFN-γ, CD3+, CD4+ T-cells, and CD4+/CD8+ ratio returned to the baseline values in group A. In contrast, the above remain decreasing in group H, where there were no significant relations between serum neopterin and IFN-γ. Conclusion: Perioperative surgical trauma and stress have an immunosuppressive impact on gastric cancer patients. Allogeneic blood transfusion exacerbates the impaired immune response. Autologous blood transfusion might be significantly beneficial for immune-compromised patients in the perioperative period, clearly showing its superiority over allogeneic blood transfusion.
doi:10.1631/jzus.2007.B0560
PMCID: PMC1934950  PMID: 17657857
Transfusion-induced immunomodulation (TRIM); Autologous blood transfusion; Allogeneic blood transfusion; Neopterin; Interferon-gamma (IFN-γ); CD3+; CD4+; CD4+/CD8+ ratio

Results 1-6 (6)