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1.
AIM: To investigate the effect of diazoxide (D) postconditioning on Cardiac function and mitochondrial 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 (50 μmol/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 (100 μmol/L) in K-H perfusion for 5 min before diazoxide postconditioning, then reperfusion for 20 min. The heart rate, coronary outflow volume, heart function, 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 observed. 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.  相似文献   

2.
AIM and METHODS:To study the damage effects of free radicals from electrolyzed krebs solution(direct current,10 mA,1-2 min) on isolated guinea pig coronary and airway tube. RESULTS:In Langendorff’s perfused guinea pig hearts,the electrolyzed free radicals increased coronary perfusion pressure(4.4±1.2) kPa,inhibited myocyte contractility [(0.8±0.8) g vs (2 9±0 6) g, P< 0.05],increased TBARS level and decreased SOD activity.In isolated perfused lungs of guinia pig,electrolyzed Krebs solution promoted significantly the airway perfusion pressure [(0.03±0.01) kPa vs (2.20±0.29) kPa, P< 0.01] and histamine reactivity [(0.65±0.37) kPa vs (2.05±0.25) kPa, P< 0.01]. Hydroxyl radicals scavenger DMSO and natural medicine gypenosides prevented the effects of oxygen free radicals. CONCLUSION: These results indicated that the free radicals by electrolyzation could induce damages of coronary endothelium and airway epithelium.  相似文献   

3.
AIM: The study was undertaken to explore the dynamic changes of the concentration of nitric oxide(NO) in ischemic myocardium and its mechanism.METHODS: In vivo myocardial ischemia of mice and in vitro perfused isolated heart of rat were used in the experiment. The effects of severity and time of ischemia on NO production, NOS activity and mRNA were examined, respectively. RESULTS: There was a considerable difference (P<0.01) in the concentration of NO between ischemia group [(9.12±1.40) μmol/L] and control group [(20.16±1.67) μmol/L] after Pit(30 U/kg) administration, and the concentration of NO of ischemic group significantly decreased [(9.17±1.33) μmol/L] compared with control group [(19.90±1.95) μmol/L] after 30 minutes of ischemia. Also, the concentration of NO after Pit(20 U/L) administration in K-H and 15 min of ischemia was (15.41±2.00) μmol/L and (15.09±2.00) μmol/L respectively in vitro, significantly lower than control group [(23.83±2.33) μmol/L and (23.63±2.52) μmol/L]. In addition, compared with control group, the number of NOS positive cells, NOS activity as well as mRNA expression in atrial muscle and ventricular muscle of ischemic group were markedly reduced, respectively. CONCLUSION: Myocardial ischemia could reduced the NO level in myocardium, down-regulation of NOS mRNA could be the possible mechanism.  相似文献   

4.
AIM:To study the correlation of serum uric acid (UA) level with carotid plaques and arterial stiffness in the patients with essential hypertension (EH), and to explore the predictive value of serum UA for evaluating EH preclinically. METHODS:A total of 92 patients with EH and 30 healthy individuals were enrolled. The value of UA and other indicators were detected. B-mode ultrasound examination was performed to measure the common carotid artery intima-media thickness (IMT) and the sites of plaque in the internal carotid-artery, external carotid artery and carotid bifurcations. Carotid-femoral arterial pulse wave velocity (CFPWV) was assessed by Complior atherosclerosis measurement instrument. RESULTS:The serum level of UA in the patients with EH was higher than that in control group [(361.51±83.81) μmol/L vs (317.03±62.22) μmol/L, P<0.05]. The mean value and abnormal rate of IMT between hypertension group and control group were significant difference [(0.69±0.14) mm vs (0.60±0.12) mm, 42.39% vs 10.00%, P<0.05]. In 92 EH patients, 45 cases had carotid plaques. These 45 cases were divided into 3 groups according to the plaque severity, among which the serum UA level had statistically significant differences [(285.25±78.41) μmol/L, (341.19±63.99) μmol/L and (401.33±88.49) μmol/L, P< 0.05]. Compared with rigid plaque group (n=34), the serum UA level in soft plaque group (n=11) was significantly higher [(389.00±69.45) μmol/L vs (323.03±72.71) μmol/L, P<0.05]. A stepwise multiple linear regression analysis demonstrated that age (r=0.414), systolic blood pressure (r=0.224), pulse pressure (r=0.270) and uric acid (r=0.219) were predisposed factors for higher CFPWV (P<0.05). CONCLUSION:UA is one of the risk factors causing hypertension. Serum UA level may reflect the severity and stability of carotid plaques. The increased arterial stiffness is closely related to the increased serum UA level in EH.  相似文献   

5.
AIM: To investigate the effects of nicotine on activation of PMNs, adhesion of PMNs-HUVEC and expression of ICAM-1 mRNA in HUVEC. METHODS: Activation of PMNs was measured by detecting the activity of β-glucuronidase and lysozym of PMNs. Adhesion of PMNs and HUVEC was observed. Northern blot was conducted for quantitating ICAM-1 mRNA. RESULTS: Nicotine could increase the activity of β-g [(8.76± 1.01)μg/107·h vs(14.87±2.00)μg/107·h,P<0.05]and Lysozym [(20.0±1.5)μg/107·h vs(36.5±4.4)μg/107·h,P<0.05], and also could promote adhesion of PMNs-HUVEC(38.5±9.8 vs 61.0±4.4,P<0.05). The expression of ICAM-1 mRNA was induced by nicotine in dose-dependent fashion (10-5-10-3mol/L).After a 2 h treatment of HUVEC with nicontine(10-4mol/L), the level of ICAM-1 mRNA is above the control(1.23 vs 1.63) and the highest level (2.03) is at a 12 h treatment. 764-3 can obviously counteract the above effect of nicotine. CONCLUSIONS: Nicotine could activate PMNs, enhance adhesion of PMNs-HUVEC and increase the expression of ICAM-1 mRNA in HUVEC.  相似文献   

6.
AIM: To study the relationship between the disturbance of nitric oxide/endothelin-1(NO/ET-1) and hepatic ischemia/reperfusion(I/R) injury as well as the regulation of NO/ET-1 system by hepatic ischemic preconditioning(IPC). METHODS: The changes of NO/ET-1 system and their relationship with hepatic I/R injury were compared between I/R group and IPC+I/R group in a rat hepatic I/R model. Two hours after reperfusion, the liver tissues were detected by RT-PCR to see whether there was inducible nitric oxide synthase (iNOS) mRNA expression. RESULTS:In the acute phase of hepatic reperfusion, the ratio of NO/ET-1 was reduced, which was due to a significant reduction of NO2-/NO3- (the metabolic product of NO) and significant elevation of ET-1 in the blood plasma. The content of ALT, AST, LDH and TNF-α in blood plasma, and of MDA in liver tissue were increased but ATP in liver tissue was reduced, the hepatic damage was deteriorated. The protection of the hepatic IPC was concerned with the elevation of the ratio of NO/ET-1 caused by the elevation of NO2-/NO3-, and reduction of ET-1 as well. There was no iNOS mRNA detected in the liver tissues.CONCLUSION: Hepatic I/R injury is related to the disturbance of NO/ET-1. The protection of the hepatic IPC in the acute phase might be conducted by its regulation of NO/ET-1 system. The cNOS rather than the iNOS generated the NO in this situation.  相似文献   

7.
AIM:To investigate probable protective mechanism of non-wounded legs ischemic preconditioning on ischemia/reperfusion(I/R) myocardium. METHODS: 36 male SD rats, weighting (250±30) g,were divided into 4 groups.They are normal control(NC);I/R; classical ischemic preconditioning(C-IPC)and non-wounded legs ischemic preconditioning(N-WIPC). NO in plasm,expression of myocardial HSP 70 mRNA, the activities of 5’-NT and CAT of myocardium were observed in all groups. RESULTS:The level of NO in plasm significantly enhanced in groups C-IPC and N-WIPC compared with that in groups I/R and NC ( P <0.01),expression of myocardial HSP 70 mRNA was greatly increased in both C-IPC and N-WIPC groups, the activities of 5’-NT, CAT of myocardium were also raised in groups C-IPC and N-WIPC ( P< 0.05 vs I/R),but there was no difference between C-IPC and N-WIPC( P >0.05). CONCLUSION:The possible protective mechanism involved in N-WIPC is similar to that in C-IPC, which is due to increase of endogenous myocardial protective substances.  相似文献   

8.
AIM:To investigate whether liver X receptors (LXRs) attenuate myocardial ischemia-reperfusion (I/R) injury in isolated rat heart through modulating glucose transporter 4 (GLUT-4). METHODS:Isolated rat hearts were used to establish the model of ischemia-reperfusion injury using Langendorff apparatus. The hearts were divided into 7 groups: LXR agonist T0901317 (0.1, 0.5 and 10 μmol/L) pretreatment groups, ischemic preconditioning group, control group, control+DMSO group, and I/R group. The releases of lactate dehydrogenase (LDH) and creatine kinase (CK), the infarct size, the hemodynamic parameters (left ventricle developed pressure,left ventricle end-diastolic pressure, coronary flow and ±dp/dt max), the relative mRNA level of GLUT-4 and the protein content of GLUT-4 in the myocardial cell membrane were compared between these groups. RESULTS:Besides producing hemodynamic disorders, I/R increased the activities of LDH and CK, and the infarct size in model groups. Treatment with T0901317 significantly suppressed ischemia-reperfusion injury-induced increases in LDH and CK, and reduced the infarct size. T0901317 also significantly ameliorated the parameters of haemodynamics. Treatment with T0901317 significantly increased GLUT-4 expression at mRNA and protein levels in the myocardial cell membrane. CONCLUSION:Liver X receptors may attenuate myocardial ischemia-reperfusion injury in isolated rat heart by modulating the expression of GLUT-4.  相似文献   

9.
AIM:To investigate the effect of ginkgo-dipyridamole injection (GD) on ischemia/reperfusion (I/R) injury in rat hearts in vitro and its possible mechanism. METHODS:Forty male Sprague-Dawley rats were randomly divided into 5 groups (n=8): normal control (NC) group, I/R group, ischemic preconditioning (IPC)+I/R group, GD+I/R group and GD+LaCl3+I/R group. Cardiac function indexes, including heart rate (HR), left ventricular systolic pressure (LVSP) and the maximal rise/fall rate of left ventricular pressure (±dp/dtmax), were detected at 5 time points, including stabilizing point, 30 min after ischemia, and 5, 30 and 60 min after reperfusion. The activity of lactate dehydrogenase (LDH) and creatine kinase (CK) in coronary effluent at the five time points was assayed. The concentration of Ca2+ and the content of α-ketoglutarate dehydrogenase (α-OGDH) in myocardial mitochondria were determined at the end of the whole experiment. RESULTS:Compared with I/R group, the cardiac function indexes in IPC+I/R and GD+I/R groups were improved at the reperfusion period (P<0.05), the activity of LDH and CK in coronary effluent and the concentration of Ca2+ in mitochondria were significant reduced (P<0.01), and the content of α-OGDH was increased (P<0.05). However, the protective effect of GD was inhibited by LaCl3 (P<0.05). CONCLUSION:GD protects rat hearts against I/R injury by inhibiting calcium overload and improving mitochondrial enzyme activity to stabilize mitochondrial energy metabolism.  相似文献   

10.
AIM:To observe the changes in nitric oxide(NO) and peroxynitrite anion (ONOO- ) in the injuried lung following the ischemia-reperfusion of hind limbs and evaluate the contribution of NO and ONOO- to tissue injury.METHODS:A model of hind limbs ischemia was made by clamping infrarenal aorta with a microvascular clip and lung injury occurring after reperfusion.Lung t issue was obtained from the animals received sham operation(group 1),4 hours ischemia without reperfusion(group2),1 hour reperfusion following 4 hours ischemia(group3)and 4 hours reperfusion fol owing 4 hours ischemia(group4).The contents of MDA,NO2-/NO3- and the activities of SOD in the lung were examined.Immunohistochemical echnique was used to determine the immunoreactivity to iNOS and nitrotyrosine(NT)-a specific "footprint" of peroxynitrite.RESULTS:Compared with group1 and group2,the contents of MDA and NO2-/NO3- increased significantly (P<0.05) and the activities of SOD decreased markedly(P<0.05) in group3 and group4.Immunohistochemical examination demonstrated intense staining for iNOS and NT throughout the lung in group3 and group4.CONCLUSION:NO and ONOO- are involved in oxidant-mediated lung injury following reperfusion of ischemic hind limbs.  相似文献   

11.
AIM: To observe the effects of adiponectin(APN) on the expression of connexin 43 (Cx43) in rat myocardium during ischemia-induced arrhythmias. METHODS: The SD rats were randomly divided into 4 groups (n=12): sham operation group (SM group), ischemia and reperfusion group (I/R group), I/R+adiponectin(APN1) group: pre-ischemia with 3.5 μg/kg of APN; I/R+APN2 group: post-ischemia with 3.5 μg/kg of APN. The incidence of ventricular arrhythmias and ventricular arrhythmia score (VAS) were determined. The expression of Cx43 in the ischemic myocardium was studied by the techniques of immunohistochemistry and RT-PCR. The levels of malondialdehyde(MDA) and superoxide dismutase(SOD) were measured by the methods of xanthine oxidase and thiobarbituric acid. The expression of endothelial nitric oxide synthase (eNOS) at mRNA and protein levels was determined by RT-PCR and Western blotting,respectively.The morphological changes of the myocardial tissues were observed under electronic microscope. RESULTS: The VAS and concentration of MDA increased obviously and the activity of SOD was decreased in I/R group as compared with SM group (P<0.01). The expression of Cx43 was evidently decreased and the distribution of Cx43 in the myocardium was disturbed. The expression of eNOS at mRNA and protein levels was decreased in I/R group (P<0.05). The ultrastructure of ventricular myocardium was abnormal in I/R group. Compared with I/R group, APN obviously decreased the VAS caused by ischemia and reperfusion (P<0.01) no matter the drug was given before or after ischemia. APN increased the activity of SOD, inhibited the MDA content in serum, and resulted in normal distribution of Cx43 and increased the expression of Cx43 and eNOS. Compared with I/R group, the changes of heart ultrastructure attenuated greatly in APN group, but didn't recover to normal state. CONCLUSION: Adiponectin antagonizes the arrhythmias during myocardial ischemia and reperfusion via inhibiting oxidative stress and regulating Cx43.  相似文献   

12.
AIM: To observe the effect of exogenous spermine (low concentration) on myocardial ischemia/reperfusion injury in rats.METHODS: 40 Wistar rats were randomly divided into 4 groups: sham- operation group (Sham), ischemic reperfusion group (I/R), spermine group (Sp) and natural saline group (NS). The model of ischemic/reperfusion injury was established by ligating rat coronary artery. In Sp group, spermine (0.5 mmol/L, 2 mL/kg) was injected slowly into rat vein. During the process, we recorded the electrocardiogram and the LV functional parameters, assayed the levels of SOD, LDH, NO and MDA in serum, and examined the ultrastructure of the myocardium. RESULTS: In I/R group, the incidence of arrhythmia was 90%, myocardial ultrastructure was injured seriously, values of LVSP and ±dp/dtmax decreased, levels of LDH, NO and MDA increased while SOD activity decreased (P<0.05 or P<0.01, compared with Sham group). Compared with I/R and NS group, all those indexes in Sp group changed significantly (P<0.05 or P<0.01). CONCLUSION: Exogenous spermine alleviates myocardial ischemia/ reperfusion injury in rats. The mechanism may be related to its antioxidant effect and relieving the injury caused by oxygen free radical.  相似文献   

13.
AIM: To establish and evaluate a rat model of heart ischemia-reperfusion injury in vivo. METHODS: Seventy-two male Sprague-Dawley rats weighing(250±50)g were randomly divided into sham operation group(sham), ischemia-reperfusion group(I/R) and normal group. The animals were anesthetized and heparinized. Myocardial ischemia-reperfusion was induced by ligating the left anterior descending coronary artery with "U-shape tube" for 35 min followed by 120 min or 240 min reperfusion in vivo. The heart infarct size was measured by triphenyltetrazolium chloride(TTC) staining. The myocardial cell apoptotic index was determined by the method of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling(TUNEL). Immunohistochemical method was used to detect the expression of Bcl-2 and Bax in rat ischemia myocardium. The blood level of MB isoenzyme of creatine kinase(CK-MB),cardiac troponin I(cTnI),nitric oxide(NO),malondialdehyde(MDA), total superoxide dismutase(T-SOD)and glutathione peroxidase(GSH-Px) were detected after reperfusion for 2 h and 4 h. RESULTS: Compared with normal group and sham group, there were obvious changes of ST-T segment and Q wave in the electrocardiogram of I/R group. The blood level of CK-MB, cTnI, NO, MDA and GSH-Px in I/R group increased(P<0.05,P<0.01) after reperfusion for 2 h and 4 h, and the blood level of T-SOD in I/R group after reperfusion for 2 h and 4 h also increased(P<0.05). The heart infarct size in I/R group was the largest as compared to other groups. Among these groups, the apoptotic index of I/R group was the highest and the Bcl-2/Bax ratio in I/R group decreased(P<0.01).CONCLUSION: The rat model of heart ischemia-reperfusion injury in vivo can be successfully established with the "U-shape tube". There are obviously changes of heart infarct size, blood level of CK-MB, cTnI, NO, MDA, T-SOD and GSH-Px, myocardial apoptotic index and Bcl-2/Bax ratio between I/R rats and control animals.  相似文献   

14.
AIM:To observe the protective effect of non-wounded ischemic preconditioning on ischemic/reperfusion injury in isolated rat hearts. METHODS: 25 male SD rats, weighting (250±30) g, were randomly divided into three groups: control group (C,n=8), anoxia/reoxygenation group (A,n=8) and non-wounded legs ischemic preconditioning group (N-WIP,n=9).Hearts were isolated from rats and perfused on a Langendorff apparatus with a normal Krebs-Henseleit buffer (saturation 95% O2+5% CO2) at a constant pressure (8.33 kPa) and temperature (37 ℃) in C group; Following 15 min equilibration, hearts were subjected to 15 min of global ischemia and 15 min reperfusion (37℃) in A group; Rats were subjected to non-wounded leg repeated-brief ischemic preconditioning, and then treated in procedure similar to A group in N-WIP group.The activities of superoxide dismutase (SOD) and Ca2+-Mg2+-ATPase, malondialdehyde (MDA) content of efflux from coronary vessel and myocardium, myocardium monophasic action potential and contractile force were measured before ischemia, 15 minutes after ischemia and 5, 15 minutes after reperfusion. RESULTS:Compared with A group, non-wounded legs ischemic preconditioning reduced the incidence of reperfusion arrhythmias (P<0.05), decreased the content of MDA of myocardium (P<0.01), enhanced the activities of SOD (P<0.01) and stabilized myocardial membranous potential,the activity of Ca2+-Mg2+-ATPase and contractile function. CONCLUSION:These results indicate that non-wounded leg ischemic preconditioning has a protective effect on ischemia-reperfusion injury in isolated rat hearts. The mechanism may be related to the strength of antioxidation, the stability of Ca2+-Mg2+-ATPase activity and membranous structure in myocardium.  相似文献   

15.
ATM: To investigate the effects of postconditioning of zacopride, a specific agonist of inwardly rectifying potassium channel (Kir), on ischemia/reperfusion-induced arrhythmias and the involved electrophysiological mechanisms. METHODS: Langendorff-perfused SD rat hearts or anesthetized rats were subjected to coronary artery occlusion for 15 min followed by 15 min of reperfusion to induce ischemia/reperfusion arrhythmias. Zacopride was applied 3 min before reperfusion. Various arrhythmias were monitored and compared in different groups. The single rat ventricular myocyte was isolated by collagenase digestion. The effects of zacopride on hypoxia/reoxygenation-induced delayed afterdepolarizations (DADs) and ATP-sensitive potassium channel (KATP) were observed by the technique of whole-cell patch clamping. RESULTS: Post-conditioning of 0.1~10 μmol/L zacopride significantly prevented the hearts from reperfusion arrhythmias. During reperfusion, 0.1 μmol/L zacopride showed the maximum effect, with decreasing the number of premature ventricular beats (PVB), reducing the incidences of ventricular tachycardia (VT) and ventricular fibrillation (VF), and shorte-ning the duration of VT and VF (P<0.01). The postconditioning effects were partly reversed by 1 μmol/L BaCl2(P<0.01), suggesting that the antiarrhythmic effect of zacopride was mediated by Kir. In the in vivo study, 1.5~5 μg/kg zacopride had positive effects on reperfusion-induced VT and VF and negative effect on PVB. At the dose of 1.5 μg/kg, zacopride showed the most potent antiarrhythmic effect, which compared favourably with that of a classical antiarrhythmic agent, lidocaine. Furthermore, zacopride significantly inhibited hypoxia/reoxygenation-induced DADs (P<0.01). Zacopride had no effect on KATP.CONCLUSION: The inhibitory effect of zacopride on ischemia/reperfusion-induced arrhythmias is mediated by the activation of Kir. Augmentation of Kir cuvrent, thus diminishing the DADs, might be the critical mechanisms underlying postconditioning of zacopride.  相似文献   

16.
AIM: We studied the therapeutic effect and mechanism of transmyocardial laser revascularization (TMLR) for the acute myocardial ischemia (AMI). METHODS: 18 dogs were divided randomly and evenly into the control group, the AMI group and the TMLR group. A continuous wave Nd: YAG laser was used for TMLR. Concentration of lactate in artery and coronary sinus (A.Lat and CS.Lat), myocardial metabolic rate of lactate acid (MLR) and myocardial lactate extraction (MLE) were measured before the left anterior descending coronary artery (LAD) ligation and 60 min after the LAD ligation. Myocardial biopsy was made 4 h after the LAD ligation to quantitatively observe the shape and number of mitochondria in myocardial cells by a electric microscope. RESULTS: 60 min after the LAD ligation, CS.Lat were (7.63±4.27) mmol/L in the AMI and (5.78±3.98) mmol/L in the TMLR, respectively (P<0.05); MLR were (0.03±0.01) mmol·100 g-1 myocardium·min-1 in the AMI and (0.06±0.02) mmol·100 g-1 myocardium·min-1 in the TMLR, respectively (P<0.05); MLE were (12.04±3.04) in the AMI and (21.84±8.49)% in the TMLR, respectively (P<0.05). The volume density of mitochondria were (27.51±7.93)% in the AMI and (31.26±3.85)% in the TMLR, respectively (P>0.05). The area density of mitochondria were (1.25±0.18) μm-1 in the AMI and (1.64±0.28) μm-1 in the TMLR, respectively (P<0.01). The number density of mitochondria were (0.10±0.03) μm-3 in the AMI and (0.18±0.05) μm-3 in the TMLR, respectively (P<0.01). The average volume of mitochondria were (5.27±2.85) μm3 in the AMI and (2.80±0.54) μm3 in the TMLR, respectively (P<0.05). The average diameter of mitochondria were (2.06±0.36) μm in the AMI and (1.78±0.12)μm in the TMLR, respectively (P<0.05). CONCLUSION: The study suggests that TMLR may effectively improve myocardial lactatic metabolism and protect the myocardial cells from ischemic injury in dogs with the AMI.  相似文献   

17.
AIM: To investigate the effects of human urotensin Ⅱ (hUII) on in vivo mesenteric microcirculation in rats. METHODS: For recording of microcirculation images in the mesentery, the intestinal loop was mounted on the stage of an intravital microscope equipped with a TV camera. Video images of microcirculation were stored by a video cassette recorder. Temporal changes in internal diameter and microcirculatory velocity of microvesseles were measured by computer using the ImagePro software. The blood flow in intestinal wall was measured with PIMII laser Doppler perfusion Imager (Lisca Sweden). RESULTS: The internal diameters of arterioles and venules in control group were (21.4±2.3) μm and (38.1±3.6) μm,respectively. In UII group, the arterioles and venules contracted immediately after treated with UII and up to the peak at 1 min . Both microcirculatory velocity of arterioles and venules showed no significant changes in UII group (compared with control, P>0.05). The blood flow in intestinal wall increased 1 min after treated with UII and up to high peak at 5 min(6.4±1.1 perfusion unit vs control 4.2±0.9,P<0.05). CONCLUSION: hUII contracted mesenteric microvesseles in rats and increased microcirculatory blood perfusion in intestinal wall.  相似文献   

18.
AIM: To approach the changes of endostatin levels in BALB/c nude mice bearing human nasopharyngeal carcinoma(NPC) in different period (5, 10, 20, 30 and 40 days) and the relationship between endostatin and tumor's development. METHODS: BALB/c nude mice bearing NPC was reproduced by hypodermic implantation of human CNE-2 cells into right-side of axillary fossa. The level of plasma endostation was detected, and the weight of isolated tumors was measured. On the basis of the regulation of these changes, their relationships were explored. RESULTS: At 5 days [(137.61±53.41) μg/L] or 10 days [(103.06±17.33) μg/L] endostatin level had no apparent alternation in comparison with control group [(113.56±21.74) μg/L, P>0.05]. At 20, 30 and 40 days concentration of endostatin[(212.80±85.91) μg/L,(293.63±62.53) μg/L, (271.57±32.45) μg/L, respectively] were higher than that of the control group (P<0.05). Along with the development of the tumors, both the levels of endostatin and tumors weight increased. There was a positive correlation between the level of endostatin and tumor weight (r=0.687, P<0.05). CONCLUSION:These results suggested that endostatin links with the development of NPC.  相似文献   

19.
AIM:To observe the sensitivity of myocardium to ischemia/reperfusion (I/R) injury in the rats with chest radiotherapy. METHODS:The radiation-induced heart disease model was established by local 20 Gy of X-ray irradiation in the chest. Male Wistar rats (n=42) were randomly divided into 6 groups:sham trauma group, trauma group, sham trauma+sham operation group, sham trauma +I/R group, trauma+sham operation group and trauma+I/R group. The rats were subjected to 30 min of ischemia and 1 h of reperfusion 2 week after trauma. The left ventricular developed pressure (LVDP) and ±dp/dtmax were recorded by BL-410 biological signal recording and analysis system. The serum cardiac troponin I (cTnI) and creatine kinase isoenzyme (CK-MB) were measured by ELISA. The myocardial infarct size was determined by nitroblue tetrazolium(NBT) staining method and BI2000 image analysis software. RESULTS:Compared with sham trauma+I/R group, significant decreases in LVDP and ±dp/dtmax were observed in trauma+I/R group (P<0.01) with significant increases in the infarct size and the concentrations of cTnI and CK-MB (P<0.01). CONCLUSION:Chest X-ray irradiation increases the sensitivity of myocardium to I/R injury in rats.  相似文献   

20.
AIM: To observe free radicals (MDA, NO) and iNOS of patients with severe acute respiratory syndrome (SARS) and to explore its significance. METHODS: MDA, NO2-/NO3- and iNOS were determined in SARS patients during the early, recovery and follow-up stage, front doctors and nurses (contact group) and health people (health control). RESULTS: The level of MDA during first stage was higher than that of recovery stage and the MDA level of recovery stage was higher than that of follow-up stage, contact group, and health control group (P<0.01). The content of NO2-/NO3- during early stage was higher than that of other groups, and the NO2-/NO3- contents of recovery stage, follow-up stage were higher than that of contact group and health control group (P<0.01), respectively. The mean of iNOS during early stage was highest than that of other stages (P<0.01) and the mean of recovery stage was higher than that of contact group (P<0.05), there were no difference in iNOS activity among any other groups (P>0.05). CONCLUSION: The pathological injury in pathogenesis of SARS is related to free radicals.  相似文献   

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