1.Effects of diazoxide postconditioning on myocardial ischemia-reperfusion injury in isolated rat hearts
Zhongxin DUAN ; Xingkui LIU ; Tian YU
Chinese Journal of Anesthesiology 2010;30(10):1163-1167
Objective To investigate the effects of diazoxide postconditioning on myocardial ischemiareperfusion (I/R) injury in isolated rat hearts. Methods Male SD rats weighing 250-300 g were anesthetized with intraperitoneal pentobarbital 40 mg/kg. Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95% O2-5% CO2 at 37 ℃. Sixty-four isolated rat hearts were randomized into 4 groups after 20 min of equilibration (n = 16 each): group control (group C), group I/R, group diazoxide postconditioning (group D) and group mito-KATP channel blocker 5-hydroxydecanoate (5-HD) + diazoxide postconditioning (group 5-HD + D). Group C received continuous perfusion for another 70 min. In group I/R, D and 5-HD + D, the hearts underwent 40 min of iscbemia followed by 30 min of reperfusion. 4 ℃ ST. Thomas cardioplegic solution was administered prior to ischemia in group I/R. Group D received 5 min of perfusion with K-H solution containing 50μ mol/L diazoxide at 5 min of reperfusion. Group 5-HD + D received 5 min of perfusion with K-H solution containing 50 μmol/L 5-HD before reperfusion with diazoxide. Eight hearts were taken at the end of equilibration and reperfusion and the indexes of cardiac function were recorded. Then the mitochondria were extracted for determination of mitochondrial membrane potential (MMP), reactive oxygen species (ROS) release, and respiratory function indexes. Results Compared with group C, MMP was significantly decreased, ROS release was significantly increased, mitochondrial respiratory function and cardiac function declined at the end of reperfusion in the other three groups ( P < 0.05 or 0.01 ). MMP was significantly increased, ROS release was significantly decreased, mitochondrial respiratory function and cardiac function were improved in group D compared with group I/R and 5-HD + D.Conclusion Diazoxide postconditioning can reduce myocardial I/R injury in rats via the opening of mito-KATPchannels and improving the mitochondrial function.
2.Effect of diazoxide postconditioning on cardiac function and mitochondri-al cardiolipin in isolated rat heart
Zhongxin DUAN ; Xingkui LIU ; Tian YU
Chinese Journal of Pathophysiology 2015;(5):812-816
AIM: To investigate the effect of diazoxide (D) postconditioning on Cardiac function and mito-chondrial cardiolipin in isolated rat heart and to explore the protective effect of ATP sensitive potassium channel on diazo-xide postconditioning myocardium.METHODS: The myocardial ischemia/reperfusion injury model in isolated rat hearts was established by Langendorff apparatus.The isolated rat hearts were randomized into 4 groups ( n=8): control group ( control) , myocardial ischemia/reperfusion injury group ( I/R) , diazoxide postconditioning group ( I/R+D) , 5-hydroxy decanoic acid (5-HD) plus diazoxide postconditioning group (I/R+5-HD+D).The hearts in each group were started with 20 min perfusion for equilibration.The hearts in control group perfused for 70 min;The hearts in I/R group was global ischemia for 40 min after ischemia reperfusion at 4℃ST.Thomas cardioplegia, then reperfusion for 30 min;The hearts in I/R+D group were treated with diazoxide (50μmol/L) in K-H perfusion for 5 min after global ischemia for 40 min, then reperfusion for 25 min;The hearts in I/R+5-HD+D group were treated with 5-HD (100μmol/L) in K-H perfusion for 5 min before diazoxide postconditioning, then reperfusion for 20 min.The heart rate, coronary outflow volume, heart func-tion, myocardial enzymes and myocardial mitochondrial cardiolipin at the end of perfusion in each group were determined. RESULTS:Compared with control group and I/R+D group, the heart rate, the concentration of heart phospholipid and the coronary outflow volume were reduced, the heart function was significantly impaired the contents of myocardial enzymes were increased in I/R group.However, no significant difference between I/R group and I/R+5-HD+D group was ob-served.CONCLUSION:The diazoxide postconditioning protects the myocardium by increasing mitochondrial cardiolipin content, reducing the release of myocardial enzymes, improving heart function and reducing myocardial reperfusion injury. The myocardial protective effect of diazoxide is completely blocked by 5-hydroxy decanoic acid.
3.Effect of ischemic postconditioning on mitochondrial cardiolipin synthesis during myocardial ischemia-reperfusion in rats in vitro
Zhongxin DUAN ; Xingkui LIU ; Tian YU
Chinese Journal of Anesthesiology 2015;35(6):680-683
Objective To evaluate the effects of ischemic postconditioning on mitochondrial cardiolipin synthesis during myocardial ischemia-reperfusion (Ⅰ/R) in rats in vitro.Methods Healthy male Sprague-Dawley rats,aged 16-20 weeks,weighing 250-350 g,were used in the study.The animals were anesthetized with intraperitoneal pentobarbital sodium 40 mg/kg and received intraperitoneal heparin 250 U/kg.Their hearts were excised and retrogradely perfused in a Langendorff apparatus.Sixty-four isolated rat hearts were randomly divided into 4 groups (n =16 each) using a random number table:control group (group C),Ⅰ/R group,ischemic postconditioning group (group IPO) and 5-hydroxydecanoate (5-HD) plus ischemic postconditioning group (group 5-HD + IPO).After 20 min of equilibration,the hearts were continuously perfused with K-H solution for 70 min in group C.In Ⅰ/R group,after 20 min of equilibration,the hearts were continuously perfused with 4 ℃ ST.Thomas cardioplegic solution 10 ml/kg,and exposed to 40 min of ischemia followed by reperfusion with oxygenated K-H solution at 37 ℃ for 30 min.In group IPO,after 20 min of equilibration,the hearts were subjected to 6 cycles of 10 s reperfusion followed by 10 s ischemia starting from 40 min of ischemia,and then were reperfused with oxygenated K-H solution at 37 ℃ for 28 min.In group 5-HD + IPO,after 20 min of equilibration,the hearts were perfused with K-H solution containing 100 μmol/L 5-HD (mitochondrial ATP-sensitive potassium channel blocker) for 5 min starting from 40 min of ischemia,and then the other procedures were similar to those previously described in group IPO.At 20 min of equilibration (T1) and 30 min of reperfusion (T2),HR,left ventricular developed pressure (LVDP),left ventricular end-diastolic pressure (LVEDP) and coronary flow (CF) were recorded.The coronary effluent 2 ml was collected for detection of lactic dehydrogenase (LDH) and creatine kinase (CK) activities.The mitochondria were extracted for determination of cardiolipin content.Results HR,LVDP,and CF were significantly lower,LVEDP was higher,and the LDH and CK activities in coronary effluent were higher at T2 than at T1 in the four groups.Compared with group C,HR,LVDP and CF were significantly decreased,LVEDP was increased,and the LDH and CK activities in coronary effluent were increased at T2 in the other three groups.Compared with Ⅰ/R group,HR,LVDP and CF were significantly increased,LVEDP was decreased,and the LDH and CK activities in coronary effluent were decreased at T2 in IPO group.Compared with IPO group,HR,LVDP and CF were significantly decreased,LVEDP was increased,and the LDH and CK activities in coronary effluent were increased at T2 in 5-HD+IPO group.Conclusion The mechanism by which ischemic postconditioning reduces myocardial Ⅰ/R injury is related to opening of mitochondrial ATP sensitive potassium channels and increasing mitochondrial cardiolipin synthesis in rats.
4.Reaction of astrocytes in nucleus of solitary tract after vagus nerve stimulation in rats
Guohong TIAN ; Li DUAN ; Zhiren RAO ; Zhongxin ZHAO ;
Academic Journal of Second Military Medical University 1981;0(04):-
Objective:To observe the quantitative and morphological changes of astrocytes in nucleus of solitary tract(NTS) after vagus nerve stimulation(VNS).Methods:Light and electron microscopy immunohistochemisty were used to examine the relationship between astrocytes and neurons by observing the expression of glial fibrillary acidic protein(GFAP),which is the specific protein for astrocytes. Results:Immunoreactivities of GFAP were significantly enhanced after VNS in NTS of rats. Meanwhile,the hypertrophy cell bodies and dark long processes could be seen under high power field. For electron microscopy,immunopositive GFAP astrocytes connected closely with the dendrites or axons of the neurons. The number of synapse increased remarkably after VNS compared with that of the control. Conclusion:Our data indicate that not only the neurons but also the astrocytes in the NTSs play a very important role in the process of the antiepileptic mechanism during VNS.
5.Effect of Rhizoma Alismatis extracts on oxidative stress induced by cerebral ischemia-reperfusion injury in rats
Xiaohui WU ; Zhongxin DUAN ; Xiaoxia KUANG ; Mingmin XU ; Zijing YU ; Feng DENG
Chinese Journal of Geriatrics 2014;33(7):795-798
Objective To investigate the effects of Rhizoma Alismatis extracts on oxidative stress induced by cerebral ischemia-reperfusion injury in rats,and to explore its protective mechanism in cerebral ischemia-reperfusion injury.Methods A total of 60 male SD rats were randomly divided into sham operation group,model group,Alisma orientalis group and Nimodipine positive control group (n=15,each).Cerebral ischemia-reperfusion injury model was prepared by suture method after 14 days of intragastric administration.After 24 hours,scores of neurological dysfunction,the infarct size,the water content of the brain,the malondialdehyde (MDA),superoxide dismutase (SOD),nitric oxide (NO) levels in serum and brain tissues,and the activity of inducible NO synthase (iNOS)were detected.Results As compared with the model group,Alisma orientalis group showed that the scores of neurological dysfunction,cerebral water content,cerebral infarction size,contents of MDA and NO,and the activity of iNOS were significantly reduced,and the activity of SOD was significantly increased in respectively [(2.21 ± 0.38) vs.(2.78 ± 0.43),(81.18 ± 2.09)% vs.(88.33±4.15)%,(0.26±0.07) % vs.(0.35±0.04)%,(5.92±1.64) μmol/L vs.(8.21±1.47)μmol/L,(115.48±18.65) mU/L vs.(75.52±20.78) mU/L,(28.23±4.32) μmol/L vs.(41.73±3.85) μmol/L,(15.31±1.68) mU/L vs.(23.49±3.53) mU/L,(5.41±0.68) μmol/L vs.(7.58±1.49) μmol/L,(168.57±10.65) mU/L vs.(150.11±13.62) mU/L,(14.37±0.77) μmol/L vs.(22.08±1.57) μmol/L,(9.83±0.75) mU/L vs.(13.28±1.84) mU/L,respectively,all P<0.05]Conclusions Alisma orientalis extract has the protective effect on focal cerebral ischemia reperfusion injury,and the mechanism may be related to antioxidant and scavenging free radicals.
6.Inhibiting Cytochrome C Oxidase Leads to Alleviated Ischemia Reperfusion Injury.
Zhaoyun YANG ; Zhongxin DUAN ; Tian YU ; Junmei XU ; Lei LIU
Korean Circulation Journal 2017;47(2):193-200
BACKGROUND AND OBJECTIVES: The overall purpose of this study was to investigate the role of cytochrome C oxidase (CcO) in preventing ischemia reperfusion-induced cardiac injury through gaseous signaling molecule pathways. MATERIALS AND METHODS: We used CcO inhibitor, potassium cyanide (KCN) to mimic the pre-treatment of gaseous signaling molecules in a global ischemia/reperfusion (IR) injury model in rats. Intracellular reactive oxygen species (ROS) was determined by measuring mitochondrial H2O2 and mitochondrial complex activity. RESULTS: KCN pre-treatment led to decreased infarction area after IR injury and improved cardiac function. KCN pre-treated group challenged with IR injury was associated with reduced ROS production through inhibition of activity and not downregulation of CcO expression. In addition, KCN pre-treatment was associated with enhanced expression and activity of mitochondrial antioxidase, suggesting the role of CcO in regulating IR injury through oxidative stress. CONCLUSION: KCN pre-treatment reduced the severity of IR injury. The potential mechanism could be increased endogenous anti-oxidase activity and consequently, the enhanced clearance of ROS.
Animals
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Cytochromes c*
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Cytochromes*
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Down-Regulation
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Electron Transport Complex IV*
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Infarction
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Ischemia*
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Mitochondria
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Myocardial Infarction
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Oxidative Stress
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Potassium Cyanide
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Rats
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Reactive Oxygen Species
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Reperfusion Injury*
7.Effect of pretreatment with Rhizoma Alismatis extract on cardiac function and cysteinyl aspartate specific protease-3 in ischemia-reperfusion injury of rats
Xiaohui WU ; Fei LIU ; Zhongxin DUAN ; Jiaheng WANG
Chinese Journal of Geriatrics 2018;37(11):1292-1296
Objective To observe the effect of pretreatment with Rhizoma Alismatis extract on cardiac function and cysteinyl aspartate specific protease-3 (caspase-3)in ischemia-reperfusion injury of rats.Methods Male Sprague-Dawley(SD)rats were randomized into a sham-operated group (S group),an ischemia-reperfusion group(IR group),Rhizoma Alismatis water extract group(S1 group),Rhizoma Alismatis alcohol extract group(S2 group)and Rhizoma Alismatis polysaccharide group(S3 group).At the end of 14-day of intragastric gavages,rats were subjected to 40 min(T1)of LAD(left anterior descending)coronary artery ligation (ischemia)and 120 min (T2)of ligation loosening (reperfusion),called as myocardial ischemia-reperfusion(IR)models.Then,at the end of T1 and T2,the left ventricular end diastolic pressure (LVEDP),left ventricular systolic pressure (LVSP),and maximum rise/fall rate of left intraventricular pressure(± dp/dtmax)were recorded respectively.The level of creatine kinase(CK)and lactate dehydrogenase(LDH)were determined.The area of myocardial infarction and the expression level of caspase-3 protein were tested.Results At end of T2,compared with the index values of IR group as a non-treatment control[LVEDP(6.70 ±0.22)mmHg,LVSP (86.16±15.11)mmHg,+dp/dtmax(997.99±151.03)mmHg,-dp/dtmax(663.71±68.55)mmHg,CK(10.54±2.04)U/L,LDH(296.51±7.00)U/L,the size of myocardial infarction(39.82±11.80)%and expression level of caspase-3(123.42±14.77)],the treatment groups of S1,S2,and S3 showed a lower levels of LVEDP [(5.89 ± 0.47) mmHg,(5.89 ± 0.67) mmHg,(6.07 ±0.51) mmHg],of activity of CK[(8.60± 1.67)U/L(8.90±1.27)U/L,(9.39±0.83) U/L],of LDH[(239.33±30.81) U/L,(223.63 ± 20.26) U/L,(241.19 ± 45.56) U/L],of size of myocardial infarction[(30.39 ± 5.44) %,(32.18±5.90)%,(33.12±8.16)%],and of expression level of caspase3 protein[(73.44± 15.28),(65.47±12.53),(65.05± 10.45)],(all P<0.01 or<0.05);but showed a higher levels of LVSP[(99.24±12.00)mmHg,(97.05±12.45)mmHg,(97.06±7.61) mmHg],and of ±dp/dtmax [(1 137.33±85.70)mmHg,(1 147.24±118.07)mmHg,(1 124.50±141.47)mmHg];[(604.77± 68.37)mmHg,(616.61±46.73)mmHg,(708.76±81.44)mmHg],(all P<0.01 or<0.05).Conclusions Pretreatment with Rhizoma Alismatis extract can effectively improve the cardiac function of ischemic repeffusion injury in vivo in rats,and reduce myocardial infarction size and myocardial enzyme release.The mechanism may be related to the down-regulation of apoptotic protein caspase-3 in myocardial tissue.
8.Effects of transcutaneous electrical acupoint stimulation-assisted anesthesia on pain and rapid recovery in elderly patients undergoing thoracoscopic surgery
Zhongxin DUAN ; Xiaohui WU ; Jiaheng WANG ; Fei LIU
Chinese Journal of Geriatrics 2020;39(3):323-327
Objective:To examine the effects of transcutaneous electrical acupoint stimulation(TEAS)on pain and rapid recovery in elderly patients undergoing thoracoscopic surgery.Methods:A total of 60 elderly patients undergoing thoracoscopic surgery were randomly divided into the TEAS group and the control group.Patients in the TEAS group received TEAS in bilateral acupoints of Hegu, Neiguan, Houxi and Zhigou at a frequency of 2/100 Hz for 30 min before anesthesia induction.The electrical stimulation intensity went from weak to strong, and gradually adjusted to the patient's maximum tolerance(10 to 15 mA)continuously for 30 min; TEAS continued during intraoperative anesthesia with a stimulation intensity of 30 mA and a frequency of 2/100 Hz until the end of surgery.Patients in the control group were given electrode pads at the same acupoints without electrical stimulation.Results:Compared with the control group, patients in the TEAS group were associated with significantly decreased doses of Sufentanil[(57.93±5.54)μg vs (44.30±4.03 )μg, t=-10.903, P=0.000)], Remifentanil[(1.56±0.26)μg vs (1.08±0.18)μg, t=-8.3043, P=0.000)], Propofol[(763.23±62.04)mg vs (559.20±46.44) mg, t=-14.420, P=0.000)]and Dexmedetomidine[(545.07±53.36) vs (301.67±43.27) μg, t=-19.405, P=0.000)], reduced frequency of analgesic pump pressing(9.9±2.0 vs 2.9±1.3, t=-10.903, P=0.000), decreased VAS scores 24 h(3.53±1.07 vs 1.90±0.66, t=-7.090, P=0.000)and 48 h(1.37±0.61 vs 0.93±0.37, t=-4.660, P=0.000)postoperatively.Time to regaining consciousness, extubation and detachment were also markedly shortened in the TEAS group.In addition, time to postoperative feeding and time to postoperative ambulation were also reduced.Postoperative hospitalization days( P<0.05)and anesthesia cost( P<0.01)both significantly decreased in the TEAS group compared with those in the control group.Patients in the TEAS group had lower rates of nausea, vomiting, decreased oxygen saturation, dyspnea, dizziness, agitation and lethargy, and increased heart rate and decreased mean arterial pressure after the opening of the pleura(H1)compared with those in the control group(all P<0.05). Bispectral indexes were maintained between 40 and 60 after anesthesia in both groups(all P<0.01). Conclusions:TEAS-assisted anesthesia can effectively alleviate pain in elderly patients undergoing thoracoscopic surgery and promote rapid recovery after operation.
9. Effects of different radiation on chromosome aberration in human lymphoblastoid cells
Ruifeng ZHANG ; Yayi YUAN ; Yue REN ; Zhongxin ZHANG ; Juancong DONG ; Xuhong DANG ; Lihong XING ; Yahui ZUO ; Zhikai DUAN
China Occupational Medicine 2017;44(03):341-344
OBJECTIVE: To compare the effects of ~(56)Fe~(17+),~(12)C~(6+)ion beams and~(60)Co γ rays on chromosome aberration in human lymphoblastoid cells. METHODS: The human lymphoblastoid cells were divided into 0. 1,0. 3,0. 5,0. 7,1. 0,2. 0 Gy irradiated groups and 0. 0 Gy control group. They were separately exposed to ~(56)Fe~(17+)ion beams( linear energy transfer was 400. 0 ke V/μm),~(12)C~(6+)ion beams( linear energy transfer was 26. 0 ke V/μm) and~(60)C γ rays. Chromosome specimens were harvested 48 hours after irradiation. The effects of different radiation on dicentric plus centric ring( “d + r”) aberration rate and chromosome aberration in human lymphoblastoid cells were detected by light microscope with artificial counting. RESULTS: The “d + r”aberration rates induced by 0. 3-2. 0 Gy ~(12)C~(6+)ion beams were significantly higher than those of ~(56)Fe~(17+)ion beams and~(60)Co γ rays at the same dose( P < 0. 017). Chromosome aberration cell rates of 0. 1-2. 0 Gy ~(12)C~(6+)ion beams were significantly higher than those of ~(56)Fe~(17+)ion beams and~(60)C γ rays at the same dose( P < 0. 017). At the dose range of 0. 0-2. 0 Gy,chromosome aberration effects of three kinds of radiations were gradually increased( P < 0. 01). The relative biological effectiveness of ~(56)Fe~(17+)ion beams was lower than that of ~(12)C~(6+)ion beams.CONCLUSION: The chromosome aberration induced by ~(12)C~(6+)ion beams was more serious than that of~(60)Co γ rays and ~(56)Fe~(17+)ion beams.
10.Immunostimulatory gene therapy combined with checkpoint blockade reshapes tumor microenvironment and enhances ovarian cancer immunotherapy.
Yunzhu LIN ; Xiang WANG ; Shi HE ; Zhongxin DUAN ; Yunchu ZHANG ; Xiaodong SUN ; Yuzhu HU ; Yuanyuan ZHANG ; Zhiyong QIAN ; Xiang GAO ; Zhirong ZHANG
Acta Pharmaceutica Sinica B 2024;14(2):854-868
Immune evasion has made ovarian cancer notorious for its refractory features, making the development of immunotherapy highly appealing to ovarian cancer treatment. The immune-stimulating cytokine IL-12 exhibits excellent antitumor activities. However, IL-12 can induce IFN-γ release and subsequently upregulate PDL-1 expression on tumor cells. Therefore, the tumor-targeting folate-modified delivery system F-DPC is constructed for concurrent delivery of IL-12 encoding gene and small molecular PDL-1 inhibitor (iPDL-1) to reduce immune escape and boost anti-tumor immunity. The physicochemical characteristics, gene transfection efficiency of the F-DPC nanoparticles in ovarian cancer cells are analyzed. The immune-modulation effects of combination therapy on different immune cells are also studied. Results show that compared with non-folate-modified vector, folate-modified F-DPC can improve the targeting of ovarian cancer and enhance the transfection efficiency of pIL-12. The underlying anti-tumor mechanisms include the regulation of T cells proliferation and activation, NK activation, macrophage polarization and DC maturation. The F-DPC/pIL-12/iPDL-1 complexes have shown outstanding antitumor effects and low toxicity in peritoneal model of ovarian cancer in mice. Taken together, our work provides new insights into ovarian cancer immunotherapy. Novel F-DPC/pIL-12/iPDL-1 complexes are revealed to exert prominent anti-tumor effect by modulating tumor immune microenvironment and preventing immune escape and might be a promising treatment option for ovarian cancer treatment.