Title: Changes of nicotinamide adenine dinucleotide phosphate oxidase in rat ventricular myocardium after myocardial infarction and intervention effects of apocynin
Abstract:Objective To study the changes of nicotinamide adenine dinucleotide phosphate(NADPH)oxidase in rat left ventricular myocardium after myocardial infarction(MI)and the mechanism of apocynin's interventi...Objective To study the changes of nicotinamide adenine dinucleotide phosphate(NADPH)oxidase in rat left ventricular myocardium after myocardial infarction(MI)and the mechanism of apocynin's intervention in NADPH oxidase.MethodsMI group was established by ligation of the left anterior descending(LAD)coronary artery in some male Sprague Dawley(SD)rats,while the sham-operated group underwent the same procedure without coronary artery ligation.The rats in MI group and sham-operated group were then further randomly divided into two subgroups,with one intragastrically receiving apocynin 15 mg/(kg·d)and the other saline on the second day after operation for 5 weeks.On the 6th week after operation,the rats were killed and the samples of left ventricular myocardium of non-infarcted area were taken from them.The concentration of superoxide anions(O2-)and activity of NADPH oxidase were measured by absorption spectrophotometry,and expression of the NADPH oxidase subunit gp91phox mRNA in ventricular myocardium detected with Reverse Transcription-Polymerase Chain Reaction(RT-PCR).The correlations of O2 concentration with gp91phox mRNA expression and activity of NADPH oxidase were respectively calculated.ResultsThe left ventricular weight(746.86±53.09)mg,the left ventricularweight index(2.55±0.34),the concentration of O2-[(83200±7582)RLU/mg protein,the activity of NADPH oxidase[(4.77±0.46)RLU/mg protein],and the gp91phox mRNA expression(0.69±0.06)in MI group increased significantly compared to those in sham-operated group[(418.33±35.75)mg,(1.34±0.19),(50 300±3416)RLU/mg protein,(3.38±0.35)RLU/mg protein,and(0.46±0.07)respectively](P0.01 or P0.05).The left ventricular weight(561.17±81.29)mg,the left ventricular weight index(1.91±0.22),the concentration of O2-[(53 300±5517)RLU/mg protein,the activity of NADPH oxidase[(3.62±0.32)RLU/mg protein],and the gp91phox mRNA expression(0.49±0.06)in MI with apocynin group decreased significantly compared to those in the other subgroup of MI group(P0.05).The O2-concentration was positively correlated to the activity of NADPH oxidase(r=0.76,P0.01)and gp91phox mRNA expression(r=0.82,P0.01).ConclusionThe NADPH oxidase system is activated after myocardial infarction,and the left ventricular weight increases markedly through myocardial remodelling.Apocynin,as a NADPH oxidase inhibitor,could distinctly decrease the production of O2-in ventricular myocardium by suppressing the activity of NADPH oxidase and expression of gp91phox mRNA,thus inhibiting myocardial remodelling.Read More
Publication Year: 2011
Publication Date: 2011-01-01
Language: en
Type: article
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