| IntroductionMyocardial ischemia - reperfusion injury (I/RI) is a pathologic process caused by multiple factors, such as superoxide radical, calcium overload, neurtrophil infiltration and endothelical dysfunction. The recent studies find that, nuclear factor - kappa B ( NF - KB ) play a key role in ischemia-reperfusion process.NF - KB is a member of the Rel family of transcriptional activator proteins, exist as latent forms before activation in various cells. It is composed of two subunits: p50 and p65 that consisting of Rel homo -or heterodimers, and is normally sequestered in the cytoplasm through being associated rapid response transcription factor inveolved in inflammatory reactions which exerts its effect by expressing cytokines, chemokines, and cell adhesion molecules. Various factors causes activation of NF - KB such as oxidative stress, virus, LPS. Inhibiting activation of NF - KB can reduce neurtrophil adhesion and infiltration, minimizing myocardial damage and improving heart function.We performed ischemia and reperfusion in rat hearts to appraise the effect of inhibiting activation of NF - KB and briefly discussed itsmechamisms.Materials and Method1. Experimental preparation: Healthy male spague Dawley rats weighed 200-260g were anesthetized with 20% urethanme solution (1 g.kg-1 ) , intubated, and placed on a animal respirator ( respiratory rate 55-60 min-1, tidal volume 30- 40ml . kg-1 ). ECG change of standard limb lead H was monitored continuously. Rat heart were exposured after thoracectory and were subjected to occlusion of the left coronary artery for up to 1h followed by reperfusion for up to 6h.2. Grouping; Distributing forty rats into four groups randomly, n = 10. (1)Control group (C) : not to occlude left coronary artery, inject normal saline (10mg.kg-1 ) into cauda vein. (2)Iscemia -keperfusion group (I/R). normal saline (10mg . kg-1) was injected before occlusion and rats stabilize 10 min, then occlude left coronary artery. (3)Pyrrolidine Dithiocarbamate group (PDTC) : PDTC solution (15mg . kg-1) was injected into rats'cauda vein before I/R. (4)Dan-shen Injection groups (DI) : Danshen injection (10mg kg-1) injected into rats'cauda vein before I/R..3. Measurements; Left ventricle myocardiums were indived into two half, one for 10% homogencate, the other was immersed in 10% formaldehyde solution for preparement of paretlin section and immu-nohistochemical stain. Cardiac MDA content, cardie SOD activity, and coardic MPO activity , NF - KB subunit p65 protein, ICAM - 1protein and TGFB1, protein immunostaining in the myocardium were in-vestigatd. And we obsever the pathologic change in myocardiacl section stained by HE.4. Statistics; Serial results were reported as mean + SD, comparison between two measurement date and rates were analyzed by t - test and x2 - test respectively, comparison in multiple groups date were analyzed by One - way ANOVA. The level of significance was taken as p<0.05.Results1. Change of MDA, MPO and SOD: MDA content and MPO activity of Group I/R were highter than Group C (p<0.01), and these of Group PDTC and Group DI were highter than Group I/R and Group C ( P < 0. 01). SOD activity changed contractly ( p < 0. 01). Comparison between Group PDTC and Group DI were no significant value about these items measured (P > 0. 05 ).2. Pathologic changes; In myocardium tissue of Group I/R, cells ' arrangement was distrbance, and appared dropsy or necrosis in part cells, the cross seriation of myocardiums disappear or unclear, nucle-arswere cleavaged or disappeared; while these changes was slight in myocardiums of Group PDTC and Group DI.3. IH seain analyse; NF - KB subunit p65 and 1CAM - 1 protein expression were increased in I/R hearts campared with Control Group hearts (p <0. 01) , TGFB1 protein expression change contractly (p < 0. 01). And the changes of NF - KB p65 and ICAM - 1 protein werereduced markedly in Group PDTC and DI (p <0.01) , while protein expression increase ( P < 0. 01 )...
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