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Objective Toinvestigatetheeffectsofpyrrolidinedithiocarbamate(PDTC)onexpressionofNF-κB,MMP-2andleft ventricular collagen remodeling following acute myocardial infarction in rats .Methods The myocardial infarction model in rat was induced by ligation of left anterior descending coronary artery .12 adult Sprague-Dawley rats survived 24 for h after acute myocardial infarction were randomly divided into the myocardial infarction (MI) group and the PDTC-treated(PD) group .Six rats were desig-nated as sham-operated group(SH group) .The PD group was intraperitoneally injected with PDTC (80 mg · kg -1 · d-1 ) for 28 d , the MI group and SH group were given normal saline as control .On 28 d ,the cardiac function of left ventricle was measured by ech-ocardiography .The infarct size was evaluated .The total collgen ,typeⅠcollgen ,typeⅢcollgen ,and Ⅰ /Ⅲ collgen ratio were quanti-fied histomorphometry .The mRNA and protein levels of NF-kappaBp65 and MMP-2 were determined by reverse transcription-poly-merase chain reaction(RT-PCR) and by Western blot ,respectively .Results Compared with the SH group ,the values of the total collgen ,typeⅠcollgen ,typeⅢcollgen ,and Ⅰ /Ⅲ collgen ratio in the MI group and the PD group were significantly increased ,the differen had statistical significance (P<0 .01) .The values of the total collgen ,typeⅠcollgen ,typeⅢcollgen ,and Ⅰ /Ⅲ collgen ratio in the PD group were notably decreased than those in the MI group(P<0 .01) .Moreover ,the mRNA and protein levels of NF-kap-paBp65 and MMP-2 in the PD group were lower than those in the MI group ,the difference had statistical significance(P<0 .01) . Conclusion Left ventricular collagen remodeling following acute myocardial infarction could be improved by PDTC to some extent , which mechanism could be related with inhibiting NF-kappaB activation and down -regulating the expression of MMP-2 in rats .
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Objective To explore the effect of xanthine oxidase inhibitors allopurinol on collagen remodeling of non-infarcted myocardium after myocardial infarction in rats.Methods Myocardial infarction models were produced by ligation of anterior descending coronary artery.The survivals were randomly divided into 3 groups:sham operation group, MI group and allopurinol group(50 mg/kg).On the 7th, 14th, 21st and 28th day respectively, the collagen content were examined. The type Ⅰ and type Ⅲ collagen volume fraction(CVF) and Ⅰ/Ⅲ ratio in non-infarcted zones(NIZ) were examined with PSR staining, mRNA expressions were detected with RT-PCR, the activities of xanthine oxidase(XO) and O—?2,?OH-scavenging in NIZ were examined by colorimetry.In addition, the expression of XO protein by Western blotting analysis and pathological change in LV were detected on the 28th day.ResultsCompared with sham group,the mRNA expressions, CVF of typeⅠand type Ⅲ collagen in NIZ were increased in MI group.The typeⅠ/Ⅲ ratio in NIZ was increased after decreased.The collagen content and activity of XO were boosted but the activities of O—?2,?OH-scavenging were decreased(P
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180)were 0.74?0.13,0.88?0.12,0.94?0.12 and 0.97?0.15 mm,respectively.ASI was positively related with IMT(r=0.395,P
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Objective To study the influence on heat shock protein 27 (Hsp27) and tumor necrosis factor ? (TNF-?) by inhibiting ubiquitin proteasome system in cardiac ischemia-reperfusion (I/R) rats. Methods Left anterior descending (LAD) coronary artery was ligated for 30 min and then released for 6 h in adult Sprague-Dawley rats. Five minutes before reperfusion, MG-132 (N-benzoyloxycarbonyl (Z)-Leu-Leuleucinal) at dose of 0.75 mg/kg was given by vein injection in I/R+T group, but I/R group, I group and sham group were given the same volume of sterile saline. The changes of myocardial infarct size, cardiac protein and mRNA levels of Hsp27 and TNF-? were measured. Results Compared with I/R group, the myocardial infarct size was significantly reduced (P
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Objective To explore the effect of xanthine oxidase inhibitor allopurinol on cardiomyocyte apoptosis in rats after myocardial infarction(MI).Methods MI model was established by the ligation of anterior descending coronary artery.The survivors were randomly divided into 3 groups: sham operation group(n=5),MI group(n=16) and allopurinol group(n=15,receiving allopurinol 50 mg?kg-1? d-1).After 28 days,the infarct size was measured.In non-infarcted zone(NIZ),cardiomyocyte apoptosis was detected by TUNEL;the expression of Fas was detected by immunohistochemistry;the expressions of xanthine oxidase(XO) and caspase 3 were detected by Western blot.In addition,the activities of XO and ?O-2,?OH-scavenging in NIZ were detected by colorimetry.Results Compared with sham operation group,the apoptosis index and expressions of Fas,XO,caspase 3 in NIZ were significantly increased in MI group.The activity of XO was increased but the activities of ?O-2 and ?OH-scavenging were decreased(P0.05).Conclusion Allopurinol could inhibit the cardiomyocyte apoptosis in NIZ in rats.The protective mechanism of allopurinol involves the reduction of reactive oxygen species and depression of the expressions of Fas and caspase 3.
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Objective To investigate the relationship between day and night regularity of asymptomatic ventricular presystole (VPS) and the activity of autonomic nervous system and its clinical significance Methods Thirty children with the absence of underlying organic heart disease were examined with 24 hour dynamic electrocardiogram (DCG), the function of autonomic nervous system and ventricular late potentials (VLP) Results The rate (43%, 13/30) was the day type VPS, 12 out of the 13 resulted from increased activity of sympathetic nerve The rate (30%, 10/30) was the night type VPS, all of them resulted from the activity of the vagus nerve enhanced There was a positive correlation between VPS frequency of day type and heart rate ( r =0 67, P
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Objective To investigate the influence of proteasome inhibitor MG-132 on inflammatory factors in rat model of myocardial ischemia/reperfusion. Methods Adult Sprague-Dawley rats were divided into 4 groups. I/R group: left anterior descending (LAD) coronary artery was ligated for 30 min, and then reperfused for 0, 1, 2, 6, 24 h; I/R+T group: MG-132 was used for treatment, and other procedures as I/R group; Sham operation group; Sham operation+T group. At 5 min before reperfusion, MG-132 (0.75 mg/kg) was given intravenously in I/R+T group and Sham operation+T group, and normal saline for I/R group and sham operation group. The changes of myocardial ultrastructure were checked, and the protein and mRNA levels of NF-?Bp65 and TNF-?, the number of PMN, the activity of MPO and survival of each group were detected. Results As compared with Sham operation group and Sham operation+T group, the protein and mRNA levels of NF-?Bp65 and TNF-?, the number of polymorphonuclear leucocytes (PMN) and the activity of myeloperoxidase (MPO) were significantly increased in I/R group (P