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Aim To research the changes of myocardial endoxin level in rats with myocardial ischemia reperfusion (MIR) and the protevtive effects of anti digoxin antiserum, an endoxin specific antagonist, on MIR injury. Methods Myocardial ischemia reperfusion injury models were obtained by ligating left anterior descending coronary artery 30 min followed by 45 min reperfusion. Sprauge Dawley rats were randomly divided into seven groups each with 10 rats. There were sham group, MIR group, normal saline group, verapamil group, low dose anti digoxin antiserum group, middle dose anti digoxin antiserum group, and high dose anti digoxin antiserum group. After reperfusion of left ventricular myocardium, sample of ischemia were processed immediately. Myocardial endoxin levels, Na +, K + ATPase activities, and intramitochondrial Ca 2+ contents were measured. The myocardial morphology were observed. Results Myocardial endoxin levels were significantly increased; Na +, K + ATPase activities were remarkably decreased; intramitochondrial Ca 2+ contents were remarkably raised. Meanwhile, myocardial morphology injury were remarkable in light microscope and electric microscope. Middle and high dose of anti digoxin antiserum intervention, myocardial endoxin levels were remarkably decreased; Na +, K + ATPase activities were drastically increased; intramitochondrial Ca 2+ declined. The myocardial histological morphology was significantly improved. Conclusion Antidigoxin antiserum, an endoxin antagonist, had protective effect against MIR. The mechanism maybe related to antagonizing endoxin, restoring energy metabolism, attenuating intracellular Ca 2+ overload.
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AIM To evaluate the changes of serum and brain tissue endoxin in model of bilateral cerebral hemisphere ischemic reperfusion injury, and effect of anti digoxin antiserum (an antagonist of endoxin). METHODS The bilateral cerebral hemisphere ischemic model was prepared by ligating three vascular by Kameyama's manner. SD rats were randomly divided into 7 groups and each group had 8 rats. Sham group, ischemic reperfusion group, negative control group, nimodipine group, low concentration anti digoxin antiserum group, middle concentration anti digoxin antiserum group, high concentration anti digoxin antiserum group. The blood was collected at the end of reperfusion, meanwhile rats were killed, and the bilateral cerebral hemisphere were took out and used to prepare encephlon homogenate and made into samples of light microscope. RESULTS Compared with sham group, the serum CK content increased; Brain tissue SOD activity reduced and MDA content increased importantly in ischemia reperfusion group; The levels of serum and brain tissue endoxin in ischemia reperfusion group were significantly higher, while ATPase activity in brain tissue decreased; Mitochondrial Ca 2+ content in brain tissue increased significantly and Mg 2+ content decreased significantly. In brain tissue,there was some inflammatory change and local necrosis;The rank order and structure of cell wasn't clear;The morphology of pyramidal cell was abnormal. Compared with ischemic reperfusion group, Anti digoxin antiserum reduced serum CK content; It antagonized lowering of SOD activity and increase of MDA content in brain tissue; It remarkably reduced the level of brain tissue endoxin; It reduced abnormal ion content of brain tissue mitochondrion induced by cerebral ischemic reperfusion injury; The high and middle concentration anti digoxin antiserum had a significant effect on raising brain tissue ATPase activity. It reduced neuron denaturation. CONCLUSION Cerebral ischemic reperfusion can increase the level of brain tissue and serum endoxin and higher endoxin can promote brain injury. Endoxin is a major factor involved in cerebral ischemic reperfusion injury. Anti digoxin antiserum can reduce brain tissue injury and had a protective and treatment effect on cerebral ischemic reperfusion injury by antagonizing the effect of endoxin.
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AIM: Changes of endoxin level, ATPase activities, intramitochondrial Ca2+ concentration, and gene expression of Na+-K+-ATPase isoforms in myocardium of rats with MIR and effect of verapamil were observed, in order to investigate mechanism of endoxin mediating intracellular calcium overload of myocytes. METHODS: Twenty four male Sprauge Dawley rats were randomized into 3 groups. Sham operation group: silk suture was threaded the left anterior descending coronary artery without ligature; MIR group (MIR): left anterior descending coronary artery was subjected to 30 min ligation followed by 45 min reperfusion; verapamil group: MIR model was given 5 mg/kg verapamil. Verapamil was injected via femoral vein 5 min before reperfusion. Left ventricle myocardium samples were processed immediately after reperfusion in order to measure the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase, endoxin level, and intramitochondrial Ca2+ concentration. The levels of ?1, ?2, ?3 and ?1 isoforms of Na+-K+-ATPase were measured by immunohistochemical assay. RESULTS: After MIR, the level of endoxin in myocardium was substantially increased; the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase in myocardial membrane were significantly decreased while the concentration of intramitochondrial Ca2+ was increased; the levels of the ?1, ?2, ?3 and ?1 isoforms of Na+-K+-ATPase were reduced markedly. Verapamil had only effect on reducing the concentration of intramitochondrial Ca2+. CONCLUSION: MIR increases endoxin secretion. The latter may depress the activity of Na+-K+-ATPase by changing the gene expression of ?1, ?2, ?3 and ?1 isoforms of Na+-K+-ATPase in myocardial membrane, inducing intramitochondrial Ca2+ overload.
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AIM: To observe the effect of endoxin antagonist,anti-digoxin antiserum,on endoxin level,ATPase activities,intramitochondrial total calcium concentration and gene expression of sodium pump isoforms in myocardium of rats with myocardial ischemia reperfusion(MIR).METHODS: Fifty-six male Sprauge Dawley rats were randomly divided into 7 groups.Sham operation group: silk suture threading the left anterior descending coronary artery without ligature;MIR group: left anterior descending coronary artery was subjected to 30 min ligation followed by 45 min reperfusion;normal saline group: MIR model was given 5 mL/kg normal saline;verapamil group: MIR model was given 5 mg/kg verapamil;low dose antidigoxin antiserum group: MIR model was given 8.6 mg/kg antidigoxin antiserum;middle dose antidigoxin antiserum group: MIR model was given 17.3 mg/kg antidigoxin antiserum;high dose antidigoxin antiserum group: MIR model was given 34.5 mg/kg antidigoxin antiserum.All drugs were injected into vessel via femoral vein within 5 min before reperfusion,respectively.After reperfusion,left ventricle myocardium samples were processed immediately in order to measure the activity of Na+-K+-ATPase and Ca2+-Mg2+-ATPase,endoxin level,intramitochondrial total calcium concentration and the experssion of ?1,?2,?3 and ?1 isoforms of sodium pump on mRNA and protein levels by RT-PCR and Western blotting and immunohistochemical assay,respectively.RESULTS: After MIR,the level of endoxin in myocardium was obviously increased.The activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase in myocardial membrane were significantly decreased while intramitochondrial total calcium concentration increased.The gene expression of the ?1,?2,?3 and ?1 isoforms of sodium pump at both mRNA and protein levels were reduced markedly.Only the effect of verapamil on reducing intramitochondrial total calcium concentration was observed.Antidigoxin antiserum significantly reduced the level of endoxin in myocardium,restored the activities of Na+-K+-ATPase and Ca2+-Mg2+-ATPase,reduced intramitochondrial total calcium concentration,and up-regulated the expression of ?1,?2,?3 and ?1 isoforms of sodium pump at both mRNA and protein levels.CONCLUSION: MIR results in increase of endoxin secretion.The latter depresses the activity of Na+-K+-ATPase by down-regulating the gene expression of ?1,?2,?3 and ?1 isoforms of sodium pump in myocardial membrane,and also induces intramitochondrial calcium overload,thereby mediates MIR injury.
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Aim To investigate effects and the mechanism of endoxin special antagonist anti-digoxin antiserum on heart function in myocardial anoxia-reoxygenation injury in rats. Methods The isolated Langendorff perfused rat heart model was established. Sixty Sprague Dawley(SD) rats were randomly divided intosix groups and each group had 10 rats: control group, anoxia-reoxygenation group, verapamil group, low, middle, high dose anti-digoxin antiserum groups. ECG, HR, LVDP and ?dp/dtmax were continuously recorded. The endoxin levels and intramitochondrial Ca2+ contents in myocardial tissues and nitric oxide (NO) contents in coronary artery fluence were measured after reoxygenation. Structures of mitochondrial and endothelial cells were observed by microscope. Results The anoxia-reoxygenation group showed a remarkable increase in endoxin level and intramitochondrial Ca2+ content, an obvious decrease NO content, an obvious injury of mitochondrial and endothelial cell, an obvious inhibition of heart function. Middle, high dose of anti-digoxin antiserum group could remarkably decrease endoxin level and intramitochondrial Ca2+ content; increase NO content; obviously relieve the injury of mitochondrial and endothelial cells; remarkably improve the discovery of heart function. Conclusion Anti-digoxin antiserum could inhibit the failure of heart function induced by myocardial anoxia-reoxygenation injury. Its mechanism may be related to antagonize endoxin, relieve mitochondrial Ca2+ overload, increase NO contents, and protect the function of mitochondrial and endothelial cells.
