Objective To investigete the effect of low-concentration ozone (O3) on voltage-gated calcium channels in fetal rat spinal cord neurons in vitro. Methods The spinal cord neurons were cultured in vitro and identified by immunohistochemistry staining. Then the cells were seeded into the culture dish and randomly divided into 3 groups: control group (group C, n = 5), O3 15 μg/ml (group O3-15, n = 4) and O3 20 μg/ml group (group O3-20, n = 8). The cells were exposed to O3 15 and 20 μg/ml in group O3-15 and O3-20 respectively, while the cells were exposed to air in group C. After 20 min incubation, the electrophysiological activity of calcium channels in neurons was recorded using whole-cell patch-clamp technique. Results Peak calcium current density was significantly increased in group O3-15 and O3-20 compared with group C ( P ＜ 0.05). Half-activation voltage was significantly lower in group O3-15 and O3-20 than in group C ( P ＜ 0.05). Peak calcium current density was significantly higher in group O3 -20 than in group O3-15 ( P ＜ 0.05) . There was no significant difference in half-inactivation voltage among the three groups ( P ＞ 0.05). Conclusion Low concentration of O3 can make the activation of the calcium ion channel easy in fetal rat spinal cord neurons in vitro.

Objective To evaluate the effect of preloading the epidural space with normal saline (NS) on the incidence of injury to blood vessel by epidural catheter placement for cesarean section. Methods One hundred and fifty parturients with a single baby at full term in vertex presentation scheduled for cesarean section under continuous epidural anesthesia were randomly divided into 3 groups ( n = 50 each): Ⅰ group control; Ⅱ group NS needle attached to a 5 ml syringe. Loss of resistance was used to identify the epidural space. In group Ⅰ no fluid was injected into the epidural space before insertion of catheter; while in group Ⅱ and Ⅲ NS 5 ml with or without whom blood or blood tinted fluid was withdrawn from epidural catheter was recorded. Results The number of patients in whom blood or blood tinted fluid was withdrawn from epidural catheter was significantly lower in group Ⅱand Ⅲ than in group Ⅰ but was not significantly different between group Ⅱ and Ⅲ. Conclusion Preloading the epidural space with 5 ml NS can reduce the incidence of injury to blood vessel induced by insertion of epidural

Objective To compare the effects of ischemic preconditioning versus ischemic postconditioning on myocardial ischemia-reperfusion (I/R)-induced inflammatory response in rats. Methods Forty male SD rats weighing 290-320 g were randomly divided into 4 groups ( n = 10 each): Ⅰ group sham operatin (group S); Ⅱ group I/R; Ⅲ group ischemic preconditioning (group IPC) and Ⅳ group ischemic postconditioning (group IPOC).Myocardial I/R was induced by 30 min ligation of left anterior descending branch (LAD) of coronary artery followed by reperfusion. In group IPC myocardial I/R was preceded by 3 cycles of ischemia followed by reperfusion (each lasting 5 min) while in group IPOC 3 cycles of I/R (each lasting 10 s) was started at the end of 30 min myocardial ischemia. MAP, HR and RPP ( MAP × HR) were recorded before (baseline) and at 1 and 20 min of ischemia and 60, 120 and 180 min of reperfusion. Venous blood samples were collected at 30 and 180 min of reperfusion for determination of serum concentrations of TNF-α, IL-6, high-mobility group box 1 (HMGB1) and cTnI. The animals were sacrificed at 180 min of reperfusion and the myocardial infarct size was measured. Results Myocardial I/R significantly decreased MAP and RPP and increased myocarcial infarct size, serum concentrations of TNF-α, IL-6,HMGB1 and cTnI in group I/R as compmed with group S. Ischemic pre- and postconditioning significantly increased MAP and reduced myocardial infarct size and I/R-induced increase in serum TNF-α, HMGB1 and cTnI concentrations in group Ⅲ and Ⅳ as compared with group Ⅱ (I/R). The myocardial infarct size was significantly larger and the serum concentrations of TNF-α, IL-6 and HMGB1 were significantly higher in ischemic postconditioning group than in the preconditioning group. Conclusion Ischemic preconditioning is more effective in attenuating the myocardial I/R-induced inflammatory response than the ischemic postconditioning.

Objective To investigate the effect of hydrogen sulfide postconditioning on the systolic function of left ventricle during myocardial ischemia-reperfusion (IR) in rats. Methods Part Ⅰ Adult male SD rats weighing 200-250 g were anesthetized with pentobarbital 40 mg/kg and heparin 250 U/kg. Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95% O2-5% CO2 at 37 ℃. Forty isolated rat hearts were randomly divided into 5 groups ( n = 8 each) after 20 min of equilibration: control group (group C); IR group; sodium hydrosulfide 1,10, 100 μmol/L postconditioning group (group SP1, SP10, SP100 ).In group Cthe hearts were perfused continuously for another 100 min. In group IR, the hearts were reperfused for 60 min after 40 min ischemia induced by 10 ml/kg ST. Thomas solution. In group SP1 , SP10 and SP100 the hearts were perfused with K-H solution containing sodium hydrosulfide 1, 10, 100 μmol/L for 2 min before reperfusion.LVDP and ± dp/dtmax were recorded at the end of equilibration and reperfusion. Part Ⅱ Cardiomyocytes were isolated from the male SD rats (weighing 200-250 g) and then cultured in CO2 incubator for 4 h. Sixty-four dishes of cultured myocytes were randomly divided into 4 groups( n = 16 each): control group (group C), hypoxia/reoxygenation group (group HR), hydrogen sulfide postconditioning group (group SP) and hypoxia postconditioning group (group HP). Group C were cultured continuously for 2 h. Group HR, SP and HP were exposed to 1 h hypoxia (95%N2-5%CO2 ) followed by 1 h reoxygenation. In group SP 10 μmol/L sodium hydrosulfide was added and the myocytes were then incubated for 2 min before reoxygenation. In group HP the cultured myocytes were expased to 3 min reoxygenation followed by 3 min hypoxia for 3 times before the 1 h reoxygenation. Mitochondrial membrane potential and F-actin expression were determined. Results Part Ⅰ Compared with group C, LVDP and ± dp/dtmax were significantly decreased at the end of reperfusion in group IR (P ＜ 0.05), while no significant difference was found in group SP1 , SP10 and SP100(P ＞0.05). Compared with group IR, LVDP and ± dp/dtmax were significantly increased in group SP ( P ＜ 0.05). There was no significant difference in LVDP and ± dp/dtmax among group SP1, SP10 and SP100(P ＞0.05). Part H Compared with group C, the mitochondrial membrane potential was significantly decreased in group HR and HP, and the expression of F-actin was significantly up-regulated in group HR, SP and HP ( P ＜ 0.05). Compared with group HR, the mitochondrial membrane potential was significantly increased and the expression of F-actin up-regulated in group SP and HP ( P ＜ 0.05 ). There were no significant difference in the mitochondrial membrane potential and expression of F-actin between group SP and HP ( P ＞0.05).Conclusion Hydrogen sulfide postconditioning can improve left ventricular systolic function during IR in rats by stabilizing mitochondrial membrane potential and promoting aggregation of F-actin.

Objective To investigate the protective effects of heme oxygenase-1 (HO-1) mediated by cell penetrating peptide PEP-1 on myocardium against ischemia/reperfusion (IR) injury in isolated rat hearts. Methods Healthy male SD rats weighing 220-280 g were anesthetized with intraperitoneal pentobarbital. Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95%O2-5% CO2 at 37 ℃. Eighteen isolated rat hearts were randomly divided into 3 groups ( n = 6 each): Ⅰ group sham operation (group S);Ⅱ group IR and Ⅲ group PEP-1/HO-1 + IR (group HO-1). The isolated rat hearts were perfused with an oxygena-ted (95% O2-5% CO2 ) K-H solution at 37 ℃ in a Langendorff apparatus and were subjected to 40 min of global ischemia followed by 50 min of reperfusion after 30 min of stabilization. In group Ⅲ (group HO- 1 ) the isolated hearts were perfused with 50 μmol/L PEP-1/HO-1 for 15 min before ischemia. After 50 min of reperfusion, HO-1expression, MDA content and SOD activity in myocardial tissues were determined. The activities of creatine kinase (CK) and lactic dehydrogenase (LDH) in coronary effluent fluid were measured. Results The HO- 1 expression was significanfly higher in HO-1 group than in group IR. IR induced significant increase in MDA content and decrease in SOD activity in myocardium and CK and LDH activities in coronary effluent in group Ⅱ compared with group S. PEP-1/HO-1 significantly attenuated IR-induced changes. Conciusion HO-1 mediated by PEP-1 has protective effects on myocardium ngainst IR injury in rats.

Objective To evaluate the role of by NO in reduction of myocardial ischemia-reperfusion (IR)injury by ginsenoside Rb1 preconditioning in diabetic rats. Methods Forty healthy adult male SD rats weighing 220-280 g were used in this study. Diabetes mellitus was induced by intraperitoneal streptozotocin 65 mg/kg and confirmed by fasting blood glucose ＞ 16.7 mmol/L. The animals were randomly divided into 4 groups ( n = 10each): sham operation group (group S), group IR, ginsenoside Rb1 group (group R) and L-NAME + ginsenoside Rb1 group (group LR). IR was produced by occlusion of the anterior descending branch of left coronary artery (LAD) for 30 min followed by 120 min reperfusion in group IR, R and LR. In group S, LAD was exposed but not occluded. In group LR, L-NAME 10 mg/kg was injected iv 25 min before ischemia. In group R and LR, ginsenoside Rb1 40 mg/kg was injected iv 10 min before ischemia. In group S and IR, eaqual volume of normal saline was injected instead of ginsenoside Rb1. The blood sample was taken from carotid artery at 120 min of reperfusion for determination of serum activities of creatine kinase (CK) and lactate dehydrogenase (LDH). Then the animals were sacrificed and myocadial tissues were obtained for determination of infarct size, endothelial nitric oxide synthase (eNOS) expression, MDA and NO contents, SOD activity and microscopic examination. Results The serum activities of CK and LDH were significantly increased and the myocardial infarct size was enlarged in group IR, R and LR, and eNOS expression was significantly down-regulated, MDA content was increased, and SOD activity and NO content was significantly decreased in group IR and LR compared with group S ( P ＜ 0.05). The serum activities of CK and LDH, and MDA content were significantly decreased, the myocardial infarct size was reduced, the expression of eNOS was up-regulated and the activity of SOD was increased in group R compared with group IR and LR ( P ＜ 0.05). There was no significant difference in the indices mentioned above between group IR and LR ( P＞ 0.05). Conclusion Ginsenoside Rb1 preconditioning can attenuate myocardial IR injury in diabetic rats via activation of eNOS, increase in NO production, and inhibition of the lipid peroxidation reaction.

Objective To investigate the outcomes of patients undergoing off-pump coronary artery bypass grafting (OPCABG) under morphine-fentanyl combined anesthesia. MethodsSeventy-two patients aged 41-64 yr undergoing OPCABG were randomly divided into 2 groups (n = 36 each): Ⅰ group morphine + fentanyl (group MF) and Ⅱ group fentanyl (group F). Anesthesia was induced with midazolam, etomidate, and vecuronium.Fentanyl 10-20 μg/kg was given iv when needed. The patients were mechanically ventilated after tracheal intubation. Anesthesia was maintsined with inhalation of 0.5%-2.0% isoflurane and intermittent iv boluses of vecuronium in both groups. Morphine 0.15 mg·kg-1·h-1 + fentanyl 8 μg·kg-1·h-1 were infused during operation in group MF, while in group F fentanyl 10 μg·kg-1·h-1 was infused. Morphine 0.75 mg/h was infused in group MF or fentanyl 10 μg/h in group F for postoperative analgesia after extubation. Recovery from anesthesia was assessed using a nine point (QoR) questionnaire. Pain was measured with VAS score and sedation with Ramsay sedation score ( 1 = fully awake, 6 = asleep, no response to verbal stimulus). The postoperative complications were recorded. ResultsQoR scores were significantly higher in group MF and in group F. The incidence of postoperative febrile reaction was significantly reduced in group MF. There was no significant difference in Ramsay sedation score and other postoperative complications between the 2 groups. ConclusionMorphine-fentanyl combined anesthesia is more beneficial for the prognosis in patients undergoing OPCABG compared with fentanyl combined anesthesia.

Objective To evaluate the effects of morphine preconditioning-postconditioning on ischemia-reperfusion (I/R) injury in isolated rat hearts. Methods Male SD rats weighing 180-200 g were killed after intraperitoneal injection of heparin 500 U/kg. The hearts were immediately removed and perfused in a Langendorff apparatus with K-H solution gassed with 95%O2-5%CO2 .HR and left ventricular systolic pressure (LVSP) were measured from a fluid-filled latex balloon in the left ventricle. Global myocardial ischemia was induced by interrupting perfusion for 45 min followed by 60 min reperfusion. Forty isolated rat hearts were randomly divided into 5 groups (n = 8 each): group 1 (I/R); group II morphine preconditioning (M1 ); group Ⅲ morphine postconditioning (M2); group IV M1 + M2; group V 5-hydroxydecanoate (5-HD) + M2. Group M1 was perfused with K-H solution containing morphine 3.0 μmol/L for 20 min 30 min before ischemia followed by 10 min normal K-H solution perfusion. Group M2 was perfused with K-H solution containing morphine 3.0 μmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Group 5-HD + M2 was perfused with K-H solution containing morphine 3.0 μmol/L+ 5-HD 10-4 mmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Myocardial CK-MB activity was measured and myocardial infarct size (IS/AAR) detennined (by 2,3,5-triphenyl tetrazolium staining) at the end of 60 min reperfusion. Results The preconditioning, postconditioning and combination of preconditioning and postconditioning with morphine 3.0 μmol/L perfusion for 10 min all provided cardio-protective effects in terms of IS/AAR and myocardial activation of CK-MB. Conclusion Although the combination of morphine preconditioning and postconditioning can protect the heart against I/R injury, the effects are similar to those of either of them alone, and the reason may be that either of them alone protects the heart against I/R injury via activating mitoKATP .

Objective To investigate the effects of sevoflurane on the systemic inflammatory response and cardiopulmonary function in septic shock rats. Methods Thirty-two SD rats, 8-10 months old, weighing 250-300 g, were randomly divided into 4 groups (n = 8 each): sham operation group (group S), cecal ligation and puncture (CLP) induced septic shock group (group CLP) , sevoflurane I group (group SEV, ) and sevoflurane II group (group SEV,). The abdomen was opened but CLP was not performed in group S. The septic shock was induced by CLP as described by Baker et al. Group SEV, and SEV, inhaled 2.4% sevoflurane for 30 min at 1 h and 3 h after the successful establishment of the model respectively. At 1, 3 and 5 h after septic shock, MAP and HR were recorded and arterial blood samples were taken for blood gas analysis and determination of plasma concentrations of TNF-α, IL-1, MDA and NO. The left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular fractional shortening (LVFS) and cardiac output (CO) were also detected 5 h after septic shock. The animals were killed after the detection of cardiac function. The lungs were removed for determination of W/D lung weight ratio and Evans blue (EB) content. The tissues from the heart, lung, liver and kidney were taken for detection of NF-kB activity by electrophoretic mobility shift assay (EMSA) ResultsMAP was significantly lower, HR higher, LVEDD, LVESD, LVFS, CO, pH value, PaO2 and PaCO2 lower, and W/D lung weight ratio, EB content, plasma concentrations of TNF-α, IL-1, MDA and NO, and NF-kB activity in the heart, lung, liver and kidney tissues higher in group CLP, SEV, and SEV2 than in group S (P < 0.05). NF-kB activity in the heart, lung, liver and kidney tissues and plasma concentrations of TNF-α, IL-1, MDA and NO were significantly lower in group SEV, than in group CLP and SEV2 ( P < 0.05 ), but no significant differences were found in the other indices between group SEV, and CLP and between group SEV1 and SEV2 ( P > 0.05). Conclusion Inhalation of 2.4% sevoflurane for 30 min 1 h after septic shock can inhibit the systemic inflammatory response slightly, but can not improve the cardiopulmonary function in rats with CLP-induced septic shock.

Objective To investigate the effects of cardioplegic solution containing different concentrations of emulsified isoflurane on myocardial ischemia-reperfusion injury in isolated rat hearts. Methods Fifty-six male SD rats, weighing 180-250 g, were anesthetized with intraperitoneal 20% urethane 1 g/kg and heparin 1 000 U/kg. Their hearts were excised and perfused in a Langendorff apparatus. Fifty-six isolated hearts were randomly divided into 7 groups ( n = 8 each) : St. Thomas cardioplegic solution group (group C) and St. Thomas cardioplegic solution containing 6 different concentrations of emulsified isoflurane groups (group E1-6 ). After 20 min equilibration, cardiac arrest was induced with St. Thomas cardioplegic solution 20 ml and St. Thomas cardioplegic solution containing 0.28, 0.56, 1.12, 1.68, 2.24 and 2.80 mmol/L emulsified isoflurane 20 ml at 4℃for 45 min followed by 60 min reperfusion in group C and E1-6 respectively. HR, left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP) and + dp/dtmax were recorded at the end of 20 min equilibration, 20, 40 and 60 min of reperfusion. Coronary effluent 1.5 ml was collected for determination of LDH and SOD activity and the concentration of cTnI. At the end of 60 min reperfusion, the area of myocardial infarction was calculated. Results Compared with group C, HR, LVDP, + dp/dtmax and SOD activity were significantly higher, LVEDP, LDH activity and cTnI concentration lower, and the area of myocardial infarction lower in group E4, and HR, LVDP, + dp/dtmax and SOD activity were significantly lower, LVEDP, LDH activity and cTnI concentration higher, and the area of myocardial infarction higher in group E6 and E6 ( P < 0.05) , but there was no significant difference in the above indices between group E1-3 and group C ( P > 0.05) . HR, LVDP, + dp/dtmax and SOD activity were significantly lower, LVEDP, LDH activity and cTnI concentration higher, and the area of myocardial infarction higher in group E1-3-5-6 than in group E4 (P < 0.05 ). Conclusion St. Thomas cardioplegic solution containing 1.68 mmol/L emulsified isoflurane can attenuate myocardial ischemia-reperfusion injury in isolatede rat hearts.