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1.
AIM:To investigate the protective effect of ischemic preconditioning (IPC) on hepatic ischemia-reperfusion(I/R) injury in cirrhotic rats and its possible mechanism. METHODS:Hepatic I/R was induced by Pringle maneuver. The cirrhotic rats were randomized into three groups: Group A: before 30 min of ischemia, a short period of 5 min ischemia and 5 min reperfusion were given; Group B: before 30 min of ischemia, a short period of 10 min ischemia and 10 min of reperfusion were given; Group C: 30 min ischemia only. The serum alanine transferase (ALT), hepatic Fas-mRNA, caspase-3 activity and hepatocyte apoptosis were analyzed. RESULTS:The 7-day survival rate in the group A and B were 100%, respectively. However, it was only 62.5% in the group C. After 6 h of reperfusion, the ALT levels in both group A and B were significantly lower than that of in group C, P＜0.01. The ALT level of group A was also lower than that of group B, P＜0.01. The hepatic Fas-mRNA expression, caspase-3 activity and apoptotic hepatocyte in group A were significantly lower than those of in group C, P＜0.01. CONCLUSIONS:IPC has significant protective effect against hepatic I/R injury. An IPC with 5 min of ischemia and 5 min of reperfusion has the maximal protective effect. The protective mechanism of IPC against hepatic I/R injury is via down-regulation of Fas-mRNA expression, inhibiting caspase-3 activity and subsequently inhibiting hepatocyte apoptosis. 相似文献
2.
WANG Hai-hua QI Ren-bin YU Lei WANG Zhi-gang MA Ying-zhong ZHOU Zhi-yong ZUO Bao-hua 《园艺学报》2002,18(5):535-539
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
3.
AIM: To explore the protective effect of riboflavin preconditioning on hepatic ischemia/reperfusion injury in rats. METHODS: Twenty-four Sprague-Dawley rats wererandomly divided into 3 groups (n=8): sham group, ischemia/reperfusion (I/R) group and riboflavin preconditioning (R+I/R) group. The rats in sham group and I/R group received a standard chow,while the rats in R+I/R group received a chow supplemented with riboflavin. After 4 weeks, portal vein and hepatic artery supplying the middle and left hepatic lobes were clamped with a traumatic vascular clip for induction of partial hepatic ischemia in the rats in I/R group and R+I/R group. After 1 h of ischemia, 1 h of reperfusion was conducted by removal of the clip. The activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum,the activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) in serum and liver were measured. Western blotting was employed to examine the protein expression of heme oxygenase-1(HO-1) in the liver. RESULTS: The results showed that ischemia/reperfusion injury markedly increased the activity of AST and ALT in serum, decreased the activity of SOD, and elevated the level of MDA and the activity of HO-1 in the liver as compared with sham group (P<0.01). The riboflavin pretreatment significantly decreased the activity of AST and ALT in serum, increased the activity of SOD and decreased the levels of MDA in serum and liver as compared with I/R group (P<0.01). In addition, the protein expression of HO-1 and the activity of HO-1 were elevated in R+I/R group (P<0.01). Cytoplasmic vacuolation and swelling of the hepatocytes were observed in I/R group. Treatment with riboflavin markedly alleviated the changes of liver structure. CONCLUSION: Riboflavin preconditioning has protective effect on hepatic ischemia/reperfusion injury. The mechanism may be correlated with enhancing the anti-oxidation and alleviating the reaction of lipid peroxidation. 相似文献
4.
AIM:To investigate the ameliorative effect of ischemic postconditioning (I-postC) on pia mater microcirculation in rats subjected to cerebral ischemia reperfusion (I/R) and its mechanisms.METHODS:Thirty-two male Wistar rats were randomly divided into sham, I/R, I-postC, and ischemic preconditioning (IPC) groups.The global cerebral I/R injury was induced by shunting carotid artery in rats.Pia mater microcirculation and cerebral microcirculatory perfusion were measured after reperfusion.The content of soluble intercellular adhesion molecule-1 (sICAM-1) in plasma was detected using enzyme linked-immunosorbent assay (ELISA).Myeloperoxidase (MPO), malondialdehyde (MDA), and superoxide dismutase (SOD) in cerebral tissue were detected.The expressions of vascular endothelial cell cadherin (VE-cadherin) and NF-κB p65 in cerebral tissue were assayed by Western blotting.RESULTS:(1) The disturbance of the blood flow in microvessel induced by I/R was improved significantly by I-postC.In addition, I-postC alleviated significantly the decrease in diameters of microvesseles, cerebral microcirculatory perfusion and cerebral VE-cadherin content induced by I/R (P＜0.05).(2) sICAM-1 in plasma, MPO and MDA in cerebral tissue decreased, but SOD activity in cerebral tissue increased in I-postC group, compared with those in I/R group (P＜0.05 or P＜0.01).The over-expression of NF-κB p65 induced by I/R was relieved by I-postC (P＜0.05).CONCLUSION:I-postC ameliorates pia mater microcirculation in rats subjected to cerebral I/R through suppressing the activation of polymorphonuclear neutrophils mediated by ICAM-1. 相似文献
5.
AIM:To examine the effect of cholecystokinin-octapeptide (CCK-8) on focal cerebral ischemia/reperfusion injury and its underlying mechanisms.METHODS:By using the suture model of focal cerebral ischemia and reperfusion, the effects of intracerebroventricular (icv) injection of CCK-8 and proglumide, nonselective CCK receptors antagonist, on the infarct size, regional cerebral blood flow (rCBF), and the levels of nitric oxide (NO), malondialdehyde (MDA) were observed in different brain regions of rats subjected to 1 h focal cerebral ischemia followed by 24 h reperfusion.RESULTS:(1) pretreatment with different doses of CCK-8 (0.3 μg,1.0 μg,2.0 μg or 4.0 μg) could attenuate the infarct size, but the statistically significant effects of CCK-8 were obtained only at the doses of 1.0 μg and 2.0 μg(P＜0.05). The neuroprotective effects of CCK-8 were blocked by pretreatment with proglumide. Administration of proglumide alone could worsen the ischemia/reperfusion injury. (2) CCK-8 (1.0 μg) inhibited the increase in NO, MDA levels in the ischemic core, and also inhibited the increase in NO level in the ischemic penumbra. The rCBF in the CCK-8 group was significantly higher than the normal value at 24 h after reperfusion (P＜0.05).CONCLUSIONS:These results suggest that both endogenous and exogenous CCK-8 alleviate focal cerebral ischemia/reperfusion injury. Such an action may be associated with inhibition of free radical-induced injuries and the improvement in rCBF. 相似文献
6.
AIM: To investigate the changes of the gut mucosa antioxidant system and liver, renal functions during rat intestinal ischemia-reperfusion injury. METHODS: 30 male Wistar rats underwent 45 min of intestinal ischemia by clamping the superior mesenteric artery followed by reperfusion. The levels of malondialdehyde (MDA), glutathione (GSH), the activities of antioxidant enzymes in the gut mucosa including catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), glutathione S- transferase (GST) activity and serum ALT, AST, BUN, Cr were assayed at 2, 4, 8, 12 and 24 h after reperfusion. RESULTS: The levels of MDA and GSH in the gut mucosa increased and decreased significantly at 2 h of reperfusion, respectively (P<0.05). MDA was still lower than sham at 24 h of reperfusion (P<0.05), while GSH decreased to 40% of sham at 4 h of reperfusion (P<0.01) but returned to the level of control at 12 h. The activities of CAT, SOD and GSH-Px did not show significant changes in rat after intestinal ischemia reperfusion. GST decreased 39% at 2 h of reperfusion compared with the sham group and decreased to 56% of sham at 4 h (P<0.05), but returned to the level of control at 12 h after reperfusion. Serum ALT, AST, BUN and Cr increased significantly at 2 h of reperfusion (P<0.05) and increased 208%, 100%, 103%, 41% compared with control at 4 h of reperfusion (P<0.01). However, at 24 h of reperfusion, they returned to normal. CONCLUSION: Intestinal ischemia/reperfusion diminishes GSH level and GST activity, increases MDA level and causes liver and renal reversible damages. 相似文献
7.
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
8.
AIM: To evaluate the role of calreticulin (CRT) in myocardial protection of remote preconditioning against myocardial ischemia/reperfusion injury. METHODS: Thirty SD rats were randomly divided into 5 groups: ischemia reperfusion group (IR), ischemia preconditioning group (IP), remote preconditioning group Ⅰ (RPI), remote preconditioning group Ⅱ (RPII) and pseudo-operation group (PO). The ischemia/reperfusion model was established in vivo. Hemodynamic changes of heart function were observed. Serum cardiac troponin T (cTnT), superoxide dismutase (SOD), malondialdehyde (MDA) and the expression of calreticulin in myocardium were detected. RESULTS: Hemodynamic data, serum cTnT, DA, SOD and the expression of CRT in RPI and IR group were not statistically different (P>0.05). SOD level in IP and RPII group was higher than that in IR group (P<0.05). Accordingly, cTnT, MDA and the expression of CRT in these two groups were lower than those in IR group (P<0.05). CONCLUSION: Remote preconditioning may mimic the protective effect of ischemic preconditioning. Remote preconditioning attenuates myocardial ischemia/reperfusion injury in vivo possibly through down-regulation of CRT expression in rats. 相似文献
9.
AIM: To study the stability of mouse cerebral ischemia/reperfusion model induced by the method of monofilament. METHODS: Sixty male Kunming mice were divided into 3 groups according to the body weight: group A (18-21 g), group B (22-28 g) and group C (30-35 g). Ischemia/reperfusion (I/R) model was made by middle cerebral artery occlusion (MCAO) with nylon monofilament. To evaluate the mouse MCAO model, the method of PRM2 laser Doppler was used to detect the cerebral blood flow, the neurological deficit scores were determined by Longa standard and infarction volume was detected with TTC staining. The content of malondialdehyde (MDA) and activity of superoxide dismutase (SOD) were also measured by ELISA. RESULTS: The successful rates of model establishment in both group A and group B were higher than that in group C (P＜0.05), especially the highest in group B . The mortality in group A was significantly higher than that in group B and group C (P＜0.05). The behavior scores and cerebral infarct volume in group A and group B were significantly higher than those in group C (P＜0.05). Obvious brain injury and neurological deficits were also observed in group A and group B with the higher content of MDA and the lower activity of SOD in the cerebral cortex of the injury side. CONCLUSION: There are three important factors to ensure the success and stability of MCAO mouse model induced by monofilament, i.e. the diameter of monofilament matching the body weight of the mice, the suitable length of monofilament within the blood vessel, as well as the maintaining of proper room temperature during experiment. The MDA content and SOD activity are also effective indexes for evaluating the cerebral I/R injury. 相似文献
10.
AIM: To study the relationship between nitric oxide (NO) and gastric mucosal injury induced by reserpine in rats. METHODS: Sixteen healthy male Wistar rats were randomly divided into control group and experimental group (n=8). NO contents and malondialdehyde(MDA) contents in plasma, gastric mucosa of the rats were respectively determined with Cadmium-reduct plus Greiss and TBA; nitric oxide synthase in gastric walls of the rats were observed using NADPH-diaphorase histochemistry and quantitatively measured with image analyzer. RESULTS: The NO contents in both plasma and gastric mucosa of experimental group were significantly lower than that in control group (P＜0.01),but their MDA contents were both higher than that in control group(P＜0.05,P＜0.01);the densities and A values of nitric oxide synthase (NOS)-positive nerve-cells and nerve fibers in gastric walls of experimental group were all obviously lower than that in control group (P＜0.05,P＜0.01). CONCLUSION: The mechanism of the reserpine-induced gastric mucosal injury in rats might be related to NO insufficiency arisen from the inhibition of NOS activity in NANC nerves in gastric wall,which might weaken the protection to gastric mucosa. 相似文献
11.
MA Xiao-juan WANG Hong-mei ZHANG Jian-long MA Qi YU Wen-yan LIAN Jun JI Feng-cai YU Jie 《园艺学报》2008,24(7):1297-1301
AIM: To investigate the effect and mechanism of liver ischemia/reperfusion (I/R) injury on the changes of cardiac energy metabolism and structure.METHODS: 48 healthy Wistar male rats were randomly divided into 6 groups as follows (n=8 in each group): control group (CTL), simply ischemia for 30 min without reperfusion(I group); reperfusion following ischemia for 30 min (I/R group); 2 h reperfusion following ischemia for 30 min (I/R 2 h group); 4 h reperfusion following ischemia for 30 min (I/R 4 h group) and 6 h reperfusion following ischemia for 30 min (I/R 6 h group). The level of serum endotoxin was measured. The levels of insulin and insulin antibody in heart were detected by radioimmunoassay. The contents of MDA, MPO and lactic acid in heart were also determined. RESULTS: During the process of liver I/R injury, the level of endotoxin increased in I group and I/R group and declined gradually for long time during reperfusion, but was still longer than that in CTL group (P<0.05). The level of MDA obviously increased in I group and in all reperfusion groups compared to CTL (P<0.05). The obvious significant differences among I/R 2 h group, I/R 4 h group, I/R 6 h group with CTL were observed (P<0.05). The activities of MPO obviously increased in all reperfusion groups, there was also an obvious significant difference compared with CTL and I group (P<0.05). The level of lactic acid obviously increased with prolongation in reperfusion (P<0.05), but decreased in I/R 6 h group (P<0.05). The level of insulin decreased in I/R 4 h group and I/R 6 h group (P<0.05). No difference of insulin antibody was observed among all groups (P>0.05). CONCLUSION: During the process of liver I/R injury, endotoxin is absorbed from intestine and impairment of liver detoxication leads to endotoxemia, which might play a role in the changes of the energy metabolism and structure in heart. 相似文献
12.
ZHOU Jun-lin LING Yi- ling LI Chen-li GU Zhen-yong SHI Zhong-li DING Chun-hua 《园艺学报》2001,17(2):158-160
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
13.
AIM: To investigate the effects of aminophylline used early in resuscitation on achievement ratio of resuscitation, the concentrations of plasma norepinephrine (NE), adenosine and nitric oxide (NO), and the levels of cardiac tissue endothelin-1 (ET-1) and adenosine in rats with sudden cardiac arrest. METHODS: Sixty SD rats were randomly divided into three groups: operated control (group A), epinephrine treatment (group B), and epinephrine plus aminophylline treatment (group C). Each group had 20 rats. The concentrations of plasma NE, adenosine and NO, and the levels of cardiac tissue ET-1 and adenosine were examined in group A and 30 min after survived in group B and group C. RESULTS: The duration of circulation recovered in group C was less than that in group B, significantly (P＜0.05). The rate of return of spontaneous circulation and survival to 30 min was achieved in 75% and 70% in group C, while those were achieved in 60% and 55% in group B, respectively (P>0.05). The concentrations of plasma adenosine and NE, and the levels of cardiac tissue ET-1 and adenosine in group B and group C were higher than those in group A significantly (P<0.05). The concentration of NO in group B was also higher than that in group A (P<0.01). The levels of plasma NO and cardiac tissue ET-1 in group C was lower than those in group B significantly (P＜0.05). CONCLUSION: Aminophylline as adenosine receptor antagonist used early in resuscitation not only increases the achievement ratio of resuscitation, but also decreases the levels of ET-1 and NO, so improves after-resuscitation syndrome. 相似文献
14.
AIM：To explore the effect of intervention for mast cell function before reperfusion on intestinal ischemia-reperfusion (IR)-induced early liver injury. METHODS：Adult SD rats (n=35) were randomized into 5 groups with 7 rats each: sham operation group (S group), IR group, cromolyn sodium treatment group (IR+C group, 25 mg/kg), ketotifen treatment group (IR+K group, 1 mg/kg), compound 48/80 treatment group (IR+CP group, 0.75 mg/kg). IR was induced by superior mesenteric artery occlusion for 75 min followed by 4 h of reperfusion. The agents were intravenously administered 5 min before reperfusion. The serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and histamine, and the liver levels of lactate dehydrogenase (LDH), tumor necrosis factor α (TNF-α), interleukin-8 (IL-8), malondialdehyde (MDA) and superoxide dismutase (SOD) were assessed. The liver histopathologic changes were also evaluated. RESULTS：IR resulted in severe liver injury as demonstrated by great increases in injury scores, concomitant significant increases in serum levels of AST, ALT and histamine, and liver levels of LDH, TNF-α, IL-8, and MDA, accompanied by reduced SOD activity (all P<0.05 vs S group). Treatment with cromolyn sodium or ketotifen markedly alleviated IR-mediated liver injury as confirmed by significant reduction of the above biomedical changes, whereas compound 48/80 further aggravated liver injury by dramatically enhancing the biomedical changes (all P<0.05 vs IR group). CONCLUSION：Inhibition of mast cell function before reperfusion may reduce early liver injury induced by intestinal ischemia reperfusion. Histamine, oxidative stress and inflammatory response may provide promising effects on it. 相似文献
15.
WANG Liang-rong ZHENG Liu-pu JIANG Liu-ming WANG Wan-tie ZHAO Xi-yue XIONG Xiang-qing LIN Li-na 《园艺学报》2010,26(2):322-326
AIM: To investigate the effects of non-invasive ischemic preconditioning on nitric oxide (NO)/endothelin-1 (ET-1) imbalance and gas exchange impairment following limb ischemia reperfusion in patients undergoing unilateral lower extremity surgery with tourniquet. METHODS: Twenty-seven patients aged 25-65 years, whose tourniquets duration varied from 1 h to 1.5 h and matched American Society of Anesthesiologists Physical Status Ⅰ-Ⅱ, were randomized into two groups: a control group (n=14) and a ischemic preconditioning group (IPC group, n=13) in which patients received three cycles of 5 min of ischemia/5 min of reperfusion before tourniquet inflation. Radial arterial blood gas, plasma malondialdehyde (MDA) and NO, serum ET-1 and interleukin-6 (IL-6) were measured just before tourniquet inflation(T0), 1 h after inflation(T1), and 0.5 h(T2), 2 h(T3), 6 h(T4), 24 h(T5) after tourniquet deflation. Meanwhile NO/ET-1 ratio, alveolar-arterial oxygen gradient (PA-aDO2) and intrapulmonary shunt (Qs/Qt) were calculated. RESULTS: In control group, arterial partial pressure of oxygen (PaO2) were decreased, while PA-aDO2 and Qs/Qt were increased significantly at T4 compared to the baselines at T0 (P<0.01). Plasma NO levels and NO/ET-1 ratios decreased gradually after tourniquets deflation and statistical significances were observed at T3 (P<0.01) with a valley at T4 (P<0.01) and recovered to baselines at T5. Serum ET-1, IL-6 and plasma MDA began to increase remarkably after T3 (P<0.05 or P<0.01), peaked at T4 and dropped slightly at T5. The changes above-mentioned could be well attenuated by the application of IPC (P<0.05 or P<0.01) except PaO2 (P>0.05). CONCLUSION: Clinical application of unilateral tourniquet within safe time limit (1.5 h) may lead to limb ischemia reperfusion and further pulmonary gas exchange impairment, which could be partially attenuated by the application of IPC via alleviating NO/ET-1 imbalance. 相似文献
16.
AIM: To observe the level of metallothionein (MT) in liver, aorta and plasma of rabbit with atherosclerosis (AS) in order to recognize the alteration of oxidative defense system in body when AS occurred.METHODS:Preparation of AS model of rabbit induced by having high-fat diet for eight weeks; the levels of MT and malondialdehyde (MDA) were measured in the tissues of liver and aorta and plasma of rabbit.RESULTS:The MT levels in liver tissues and plasma in atherosclerotic group increased 318%(P＜0.01) and 62% (P＜0.01), compared with control group, but its level in aortic tissue in atherosclerotic group decreased 33% (P＜0.01). The MDA levels in liver, aortic and plasma in atherosclerotic group increased 95%(P＜0.01), 76%(P＜0.01) and 42%(P＜0.01), respectively, compared with control group. The changes of contents of MT in liver and plasma have relation with level of MDA in liver tissues and plasma.CONCLUSION:The alteration of MT in liver tissues and plasma in atherosclerotic rabbits may be related to lipid hyperoxidative injury. 相似文献
17.
AIM: To evaluate the protective effect of rapid phase of ischemic preconditioning against spinal cord ischemic injury in rabbits. METHODS: Thirty six male New Zealands white rabbits were randomly assigned to 3 groups (12 in each group): ischemia and reperfusion injury group (IR group), ischemic preconditioning + IR group (IPC+IR group) and sham operation group (sham). In IR group, spinal cord ischemia was induced by an infrarenal aorta clamping for 20 min; The rabbits in IPC+IR group underwent a 6 min ischemic preconditioning followed by 30 min of reperfusion before the 20 min clamping; The rabbits in sham group underwent the same procedures as the IR group except for infrarental aortic unclamping. Neurologic status was scored at 8, 12, 24 and 48 h after reperfusion. All animals were sacrificed at 48 h after reperfusion and the spinal cords (L5-7) were removed for histopathologic study and determination of the activity of Na+, K+-ATPase. RESULTS: The neurologic function scores in sham group and IPC+IR group at each observation interval were higher than those in IR group (P＜0.01). Compared to IR group, there were more normal neurons in anterior horn of spinal cord in sham group and IPC+IR group (P＜0.01); the activity of Na+, K+-ATPase in sham group and IPC+IR group were higher than those in IR group (P＜0.01). CONCLUSION: The rapid phase of ischemic preconditioning has a protective effect against spinal cord ischemic injury in rabbits, and this neuroprotection may be related to the maintenance of Na+, K+-ATPase activity. 相似文献
18.
AIM: To investigate the effect of dexamethasone (DEX) preconditioning on reperfusion arrhythmia. METHODS: 46 Sprague-Dawley rats were divided randomly into DEX and control (CON) group, the rats were pretreated with DEX or sodium chloride before their hearts were separated for Langendorff perfusion and for ischemia/reperfusion. The reperfusion arrhythmias were observed dynamically after 60 min reperfusion following 30 min ischemia. The expression of HSP72 in myocardium was examined by Western blotting and immunohistochemistry at reperfusion 60 min. The levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and the activities of Na+-K+-ATP ase, Ca2+-Mg2+-ATPase on myocardial plasma membrane were detected. RESULTS: Compared with control group, the accumulated points and persistence time of ventricular arrhythmia were reduced significantly in DEX group (P<0.05), the expression of HSP72 was significant upregulated (P<0.05), the level of MDA was reduced significantly, the activities of SOD, CAT, GSH-Px and Na+-K+-ATPase were significantly higher (P<0.05). CONCLUSION: Dexamethasone pretreatment markedly reduces the reperfusion ventricular arrhythmias in rats, which may be attributed to upregulation of HSP72, SOD, CAT, GSH-Px , Na+-K+-ATPase and inhibition of lipid peroxidation. 相似文献
19.
LI Shu-lian LI Zai-quan ZHANG Ying XUE Lin XU Song WANG Xiao-hong TANG Chao-shu 《园艺学报》2000,16(8):678-680
AIM: To observe the changes of metallothionein (MT) in various tissues of mice during hyperhomocysteinemia. METHODS: Intraperitoneal injection of homocysteine into mice induced hyperhomocysteinemia. The contents of tissue MT and malondialdehyde (MDA) in liver, heart and kidney were determined. RESULTS: Compared with control group, tissue MT levels in Hcy-group animals were increased by 210% (P＜0.01) for liver, by 133% (P＜0.05) for heart and by 60% (P＜0.01) for kidney. Tissue MDA contents were increased by 6%, 52%(P＜0.05) and 69% (P＜0.05), respectively. However, in treated animals with Hcy plus superoxide dismutase (SOD), the tissue MT contents in liver, heart and kidney were decreased by 22% (P＜0.05), 33% (P＜0.05) and 13% (P＞0.05), respectively, compared with Hcy alone group. Tissue MDA contents were decreased by 24% (P＜0.05), 21% (P＜0.05) and 48% (P＜0.01). There was a positive correlation between tissue MT content and MDA level. CONCLUSION: Hcy could induce tissue MT formation through oxidative stress. 相似文献
20.
AIM: To investigate the influence of ischemic preconditioning on heart function, the activities of lactate dehydrogenase (LDH), malondialdehyde (MDA), and heme oxygenase-1 (HO-1) after ischemia/reperfusion in isolated rat heart. METHODS: The model of Langendorff was used in isolated rat heart perfusion. Ischemic preconditioning protocol: stopping perfusion for 5 minutes and reperfusion for 5 minutes, repeating three times. Ischemia protocol: stopping perfusion for 40 minutes and reperfusion for 20 minutes. Indexes of heart function were recorded in control M8, ischemia and reperfusion group (IR), and ischemic preconditioning group (IPC). The content of LDH of coronary effluent was measured. Moreover, the content of MDA and activity of HO-1 in myocardium were also measured. RESULTS: The recovery percentage of heart function in IPC group was significantly higher than that in IR group (P<0.01) and the activity of heme oxygenase-1 also increased significantly (P<0.05). CONCLUSION: The contents of LDH and MDA significantly decreased in IPC group compared with IR group. The increase in heme oxygenase-1 activity might be involved in the protective effect of ischemic preconditioning on ischemic/reperfused rat heart. 相似文献