OBJECTIVES: Myocardial ischemia reperfusion injury (IRI) occurs occasionally in the process of ischemic heart disease. Sevoflurane preconditioning has an effect on attenuating IRI. Preserving the structural and functional integrity of mitochondria is the key to reduce myocardial IRI. Silent information regulator 3 (SIRT3), a class of nicotinamide adenine dinucleotide (NAD⁺) dependent deacetylases, is an important signal-regulating molecule in mitochondria. This study aims to explore the role of mitochondrial NAD⁺-SIRT3 pathway in attenuating myocardial IRI in rats by sevoflurane preconditioning. METHODS: A total of 60 male Sprague Dawley (SD) rats were randomly divided into 5 groups (n=12): A sham group (Sham group), an ischemia reperfusion group (IR group), a sevoflurane preconditioning group (Sev group, inhaled 2.5% sevoflurane for 30 min), a sevoflurane preconditioning+SIRT3 inhibitor 3-TYP group (Sev+3-TYP group, inhaled 2.5% sevoflurane for 30 min and received 5 mg/kg 3-TYP), and a 3-TYP group (5 mg/kg 3-TYP). Except for the Sham group, the IR model in the other 4 groups was established by ligating the left anterior descending coronary artery. The size of myocardial infarction was determined by double staining. Serum cardiac troponin I (cTnI) level was measured. The contents of NAD⁺ and ATP, the activities of mitochondrial complexes I, II, and IV, the content of MDA, the activity of SOD, and the changes of mitochondrial permeability were measured. The protein expression levels of SIRT3, SOD2, catalase (CAT), and voltage dependent anion channel 1 (VDAC1) were detected by Western blotting. The ultrastructure of myocardium was observed under transmission electron microscope. MAP and HR were recorded immediately before ischemia (T0), 30 min after ischemia (T1), 30 min after reperfusion (T2), 60 min after reperfusion (T3), and 120 min after reperfusion (T4). RESULTS: After ischemia reperfusion, the content of NAD⁺ in cardiac tissues and the expression level of SIRT3 protein were decreased (both P<0.01), and an obvious myocardial injury occurred, including the increase of myocardial infarction size and serum cTnI level (both P<0.01). Correspondingly, the mitochondria also showed obvious damage on energy metabolism, antioxidant function, and structural integrity, which was manifested as: the activities of mitochondrial complexes I, II, and IV, ATP content, protein expression levels of SOD2 and CAT were decreased, while MDA content, VDAC1 protein expression level and mitochondrial permeability were increased (all P<0.01). Compared with the IR group, the content of NAD⁺ in cardiac tissues and the expression level of SIRT3 protein were increased in the Sev group (both P<0.01); the size of myocardial infarction and the level of serum cTnI were decreased in the Sev group (both P<0.01); the activities of mitochondrial complexes I, II, and IV, ATP content, protein expression levels of SOD2 and CAT were increased, while MDA content, VDAC1 protein expression level, and mitochondrial permeability were decreased in the Sev group (all P<0.01). Compared with the Sev group, the content of NAD⁺ in cardiac tissues and the expression level of SIRT3 protein were decreased in the Sev+3-TYP group (both P<0.01); the size of myocardial infarction and the level of serum cTnI were increased in the Sev+3-TYP group (both P<0.01); the activities of mitochondrial complexes I, II, and IV, ATP content, protein expression levels of SOD2 and CAT were decreased, while MDA content, VDAC1 protein expression level, and mitochondrial permeability were increased in the Sev+3-TYP group (all P<0.01). CONCLUSIONS Sevoflurane preconditioning attenuates myocardial IRI through activating the mitochondrial NAD⁺-SIRT3 pathway to preserve the mitochondrial function.
Adenosine Triphosphate/metabolism* ; Animals ; Male ; Mitochondria/metabolism* ; Myocardial Infarction/metabolism* ; Myocardial Reperfusion Injury/metabolism* ; NAD/metabolism* ; Rats ; Rats, Sprague-Dawley ; Sevoflurane/metabolism* ; Sirtuin 3/metabolism* ; Voltage-Dependent Anion Channel 1/metabolism*

OBJECTIVETo investigate the retrograde changes in the dorsal motor nuclei (DMV) of the vagus nerve after vagotomy in rats.

METHODSNissl staining and immunohistochemistry were used to observe the morphological and quantitative changes of the DMV and alterations of the expression of iNOS and NADPH after severing of the vagus nerve in adult male Wistar rats.

RESULTSCompared with the control group, the rats with right vagotomy showed obvious morphological changes and a significantly decreased number of neurons in the right DMV (P<0.05). Numerous iNOS- and NADPH-immunopositive cells were detected in the right DMV 5 and 10 days after right vagotomy.

CONCLUSIONVagotomy causes obvious retrograde changes in rat DMV shown by a significantly decreased number and obvious morphological changes of the neurons in the DMV.

Animals ; Male ; NADP ; metabolism ; Neurons ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Rats ; Rats, Sprague-Dawley ; Vagotomy ; Vagus Nerve ; pathology ; physiopathology ; surgery

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

OBJECTIVE: To investigate the liver protection mechanisms of MAPK signaling pathway of limb ischemia preconditioning in the late phase. METHODS: Thirty-six adult male New Zealand white rabbits, weighing 1.8-2.0 kg, were randomly divided equally into 3 groups: group C (sham operation), group L (liver ischemia-reperfusion 24 h after limb ischemia preconditioning), group IR (liver ischemia-reperfusion without limb ischemia preconditioning). Serum alanine transaminase (ALT) was measured during ischemia reperfusion. The tissue and cell injury of liver were examined by optical and electron microscopy. Activation of P38MAPK, P44/P42MAPK, and JNK in hepatic tissue was assessed by western blot after 30 min of reperfusion. RESULTS: Serum ALT and cell injury in the liver as examined by optical and electron microscopy was decreased in group L as compared with the group IR. Phosphorylation of P38MAPK, P44/ P42MAPK, and JNK were all increased significantly after 30 min of reperfusion. Phosphorylation of P38MAPK and JNK was reduced by limb ischemia pre-treatment. CONCLUSION Limb ischemia pre-treatment can induce the late phase of preconditioning in rabbit liver through the inhibition of the phosphorylation of P38MAPK and JNK.
Animals ; Extremities ; blood supply ; Ischemic Preconditioning ; methods ; Liver ; blood supply ; MAP Kinase Signaling System ; Male ; Phosphorylation ; Rabbits ; Reperfusion Injury ; prevention & control ; p38 Mitogen-Activated Protein Kinases ; chemistry ; physiology

Objective To investigate the effect of high concentration carbon dioxide preconditioning on lipid peroxidation during myocardial ischemia-reperfusion (I/R) in rabbits. Methods Twenty-four New Zealand white rabbits weighing 2.0-3.9 kg were randomly divided into 3 groups ( n = 8 each): sham operation group (group S) , I/R group, high concentration carbon dioxide preconditioning group (group H) . The amimals were tracheal intubated and mechanically ventilated. In groups S and I/R, fresh gas flow was set at 0.3 L/min (100% O2 ), respiratory rate 30-40 bpm and tidal volume IS ml/kg, and PETCO2 was maintained at 40-50 mm Hg for 30 min. In group H, fresh gas flow was set at 0.3 L/min (100% O2), respiratory rate 20-30 bpm and tidal volume 10 ml/kg, PETO2 was maintained at 75-85 mm Hg for 5 min, and then all the ventilatory parameters were adjusted to the same as those in groups S and I/R. Myocardial I/R was produced by occlusion of left anterior descending branch of coronary artery for 30 min followed by 3 h reperfusion after preconditioning in groups I/R and H. The animals were sacrificed at the end of reperfusion and myocardial tissues obtained for determination of the superoxide dismutase (SOD) activity and malondialdehyde (MDA) content and examination of the ultrastnicture of myocardium with the transmission electron microscope. Results The SOD activity was significantly lower, while MDA content higher in group I/R than in group S ( P ＜ 0.01) . The SOD activity was significantly higher, while MDA content lower in group H than in group I/R ( P ＜ 0.01) . The myocardial injury was attenuated in group H compared with group I/R. ConclusionHigh concentration carbon dioxide preconditioning can reduce myocardial I/R injury in rabbits through inhibiting lipid peroxidation.

OBJECTIVE: To investigate the changes of myocardial protein expression profiles in 2-chloro-N6-cyclopentyladenosine (CCPA), an adenosine A1 receptor agonist-induced delayed myocardial protection in New Zealand rabbits . METHODS: A total of 8 rabbits were randomly divided into a CCPA group (CCPA group) and a normal saline group (NS group). CCPA and NS were infused into rabbits in the CCPA group and the NS group respectively. Twenty-four hours later, the rabbits were subjected to 30 min left anterior descending coronary artery occlusion and were reperfused for 2 hours, then the ischemic zone tissues of left ventricle were sampled for proteomic analysis.A total of 12 other New Zeland rabbits were divided into a sham group (Sham group), a normal saline group (NS group) and a CCPA group (CCPA group). The expression of αB-crystalline, one of the differential proteins, was confirmed by Western blot. RESULTS: Analysis of two dimensional gel electrophoresis showed that the expression of 55 protein spots were different between the two groups, 17 protein spots were preliminarily identified with the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and Mascot and Expasy bioinformatics software. These proteins included stress proteins, metabolism-associated proteins, signal transduction pathway-related proteins, ionophorous proteins, immunity-associated proteins, and so on. Western blot showed that the expression of αB-crystalline was significantly up-regulated in the CCPA group. CONCLUSION The myocardial protein expression profiles are changed markedly in the preconditioning late phase of CCPA .The differential proteins might be involved in the delayed cardioprotection induced by CCPA.
Adenosine ; analogs & derivatives ; therapeutic use ; Adenosine A1 Receptor Agonists ; therapeutic use ; Animals ; Female ; Ischemic Postconditioning ; methods ; Male ; Myocardial Reperfusion Injury ; metabolism ; prevention & control ; Myocardium ; metabolism ; Proteome ; analysis ; Proteomics ; methods ; Rabbits

Objective To evaluate the effect of esmolol on bispectral index (BIS) in patients undergoing orotracheal intubation during induction of anesthesia and to investigate the mechanism of inhibiting the cardiovascular responses to tracheal intubation.Methode Forty patients in physical status of ASA Ⅰ or Ⅱ and aged 20-60 years were randomly divided into 2 groups ( n = 20 each): esmolol group (group E) and control group (group C). Anesthesia was induced with midazolam 0.1 mg/kg, fentanyl 5 μg/kg and vecuronium 0.1 mg/kg. In group E, esmolol 1 mg/kg was given intravenously before anesthesia induction and followed by an infusion of esmolol 250 μg· kg- 1·min-1, while a comparable volume of saline was given for group C. Mean arterial pressure (MAP), heart rate (HR) and BIS were recorded before esmolol administration, before induction of anesthesia, before orotracheal intubation, and at 1, 2 and 5 min after intubation, respectively.Results There were no significant differences in HR, MAP and BIS between the two groups before tracheal intubation. HR and MAP significantly increased after tracheal intubation in both groups, but BIS only in group C significantly increased after intubation.HR, MAP and BIS were significantly lower after intubation in group E than in group C ( P＜ 0.05).Conclusion Esmolol can decrease BIS during tracheal intubation and its antinociceptive property is related to the mechanism of inhibiting cardiovascular responses to tracheal intubation.

Objective To investigate the role of mitochondrial permeability transition pore (mPTP) in attenuation of myocardial ischemia-reperfusion (I/R) injury by delayed preconditioning with sevoflurane in rats.Methods Eighty male SD rats, weighing 250-300 g, were randomly assigned into 5 groups ( n = 16 each): Ⅰsham operation group (group S), Ⅱ group I/R, Ⅲ sevoflurane delayed preconditioning group (group SP), Ⅳ the mPTP opener atractyloside + sevoflurane delayed preconditioning group (group A + SP), and Ⅴ atractyloside group (group A). Myocardial I/R was induced by ligation of anterior descending branch of left coronary artery for 30 min followed by 120 min of reperfusion in group I/R, SP, A + SP and A. In group SP and A + SP, 2.5%sevoflurane was inhaled for 1 h, while pure oxygen was inhaled for 1 h in the other groups, and then myocardial ischemia was performed 24 h later. In group A + SP and A, atractyloside 5 mg/kg was injected intravenously via caudal vein 15 min before ischemia. Blood samples were taken from carotid arteries for detection of serum cardiac troponin-Ⅰ (cTnI) concentrations at the end of reperfusion. Then the rats were sacrificed and hearts removed. The myocardial infarct size (IS) and expression of Bcl-2 and Bax in the myocardium were determined. Myocardial ultrastructure was examined with the electron microscope. Results Serum cTnI concentrations and Bax expression were significantly higher, the myocardial IS was significantly larger and Bcl-2 expression was significantly lower in the other groups than in group S ( P ＜ 0.05). Serum cTnI concentrations and Bax expression were significantly lower, the myocardial IS was significantly smaller and Bcl-2 expression was significantly higher in group SP than in group I/R ( P ＜ 0.05). Microscopic examination showed less damage in group SP than in group I/R. The protection provided by sevoflurane preconditioning was abolished by atractyloside. Conclusion Inhibition of mPTP opening can result in an up-regulation of Bcl-2 expression and down-regulation of Bax expression, which plays a role in attenuation of myocardial I/R injury by delayed preconditioning with sevoflurane in rats.

Objective: To investigate the function of the ATP-sensitive K+(KATP) channel activation on the protective effect of hypercarbonic acidosis preconditioning on rabbit myocardial cells. Methods: Thirty-two rabbits were randomly divided into 4 groups (n = 8 for each group): pseudo-operation group (group P), ischemia and reperfusion group(group IR), hypercarbonic acidosis group(group H) and hypercarbonic acidosis+ glybenzcyclamide group (group H+G). Animals were ventilated normally in group IR and group P, tidal volume 15 mL/kg, breathing rate 35 bpm .The PETCO_2 was maintained at the level of 40-50 mm Hg for 30 minutes. Animals received low-frequency, low volume ventilation in group H group H+G, tidal volume 10 ml/kg, breathing rate 25 bpm to achieve hypercarbonic acidosis. The target value of PETCO_2 was 75-85 mm Hg. This value was maintained for 5 minutes. The animals then were ventilated normally to make the PETCO_2 return to 40-50 mm Hg. Animals were injected with 0.3 mg/kg glybenzcyclamide 10min before achieving hypercarbonic acidosis with hypoventilation in group H+G. Animals received ligation of left anterior branch artery for 30 minutes and reperfusion for 180 minutes in each group except P group. The myocardial ischemia area, the myocardial infarction area and their ratios were calculated by the ismaeil methods. Results: The ratio of the myocardial infarction area to the myocardial ischemia was significantly less in group H than those of group IR and group H+G (P < 0.01). The value of the ratio was similar between group H+G and group IR(P > 0.05). Conclusion: Hypercarbonic acidosis preconditioning can protect the cardiomyocytes by activating the KATP channel.

OBJECTIVE: To analyze the morphine rabbit myocardium with matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry (MALDI-TOF-MS). METHODS: Six New Zealand white rabbits were randomly assigned to a control group (Group C) and a morphine group (Group M). Group C were pretreated with bolus injection of saline 1 mL/kg. Group M were pretreated with bolus injection of morphine 3 mg/kg. The myocardium tissue proteins of the rabbits 24 hours after the injection of morphine or saline preconditioned were extracted and separated by two dimensional gel electrophoresis(2-DE), and the images were analyzed and different proteins were found. Some of the different proteins were determined with MALDI-TOF-MS. RESULTS: There were 51 protein spots that displayed quantitative changes in expression (P < 0.05), 15 protein spots were chosen for MS analysis, and 8 proteins were preliminarily identified.They were aldose reductase, zinc finger protein 312, src related tyrosine kinase, carbonic anhydrase 12 precursor, electron transfer flavoprotein beta-subunit, glyceraldehyde-3-phosphate dehydrogenase, tumor necrosis factor ligand superfamily member 11 and transmembrane emp24 domain-containing protein. CONCLUSION These proteins may be involved in the cardioprotection of morphine preconditioning.
Animals ; Electrophoresis, Gel, Two-Dimensional ; Female ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Morphine ; pharmacology ; Myocardial Reperfusion Injury ; metabolism ; Myocardium ; metabolism ; Proteome ; analysis ; Proteomics ; methods ; Rabbits ; Random Allocation ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; methods