【作者】 戴成祥；

【导师】 李小鹰；

【作者基本信息】 军医进修学院 ， 老年心血管病， 2001， 博士

【摘要】 目的 (1)第一部分：研究腺昔A~1受体激动剂R-苯异丙基腺苷(R-PIA)对大鼠心率和心脏功能的调节作用及其机制。(2)第二部分：观察R-PIA能否使大鼠心肌产生药理性延迟预适应及一氧化氮合酶(NOS)、ATP敏感性钾通道(K~ATP)与心肌核因子-kappa B(NF-k B)在其产生机制中的作用，为开发腺苷类药物在心血管临床方面的应用价值提供依据。 方法 (2)第一部分：雄性Wistar大鼠40只，随机分为5组（每组8只）：生理盐水组、R-PIA 0.03mg/kg组、R-PIA 0.04mg/kg组、R-PIA0.05mg/kg组、R-PIA 0.03mg/ks+DPCPX(腺苷 A~1受体桔抗剂)0.Zm/ks组。大鼠麻醉后，经右颈动脉插管至左心室，经Cardio2心功能软件连续监测左室压力变化。观测经皮下给药前后不同时刻的心率和左室收缩压峰值(LV-PSP)、左室发展压(LV-DP)、左室压力随时间变化的最大速率(±dp/dt~max)、零负荷时心肌最大收缩速率(Vmax)、心率与左室发展压乘积 (RPP)等。实验数据经 SPSS 8.0 统计软件处理。(2)第二部分：雄性Wistar大鼠80只，随机分为5组，每组16只：生理盐水组、R-PIA组、R-PIA+DPCPX组、R-PIA+L-NNA(一氧化氮合酶抑制剂)组、R-PIA+格列苯腺(ATP敏感性钾通道桔抗剂)组。大鼠皮下给药后正常饲养24小时，麻醉，经右颈动脉置入导管至左心室，由Cardio2软件连续监测和处理左室压力变化。以多导生理记录仪监测心电变化。大鼠予以开胸并结扎左冠状动脉前降支30min，再灌注120min后，立即摘取心脏，用于心肌梗死范围测定(TTc stain)、原位心肌细胞凋亡检测(TUNEL)及心肌 NF-k B结合活 s 2 中国人民解放军军医进修学院 博士学位论文性检测（liMSA）。实验数据经SPSS 8．0统计软件处理。 结果 ＊）第一部分：①RWIA对大鼠具有剂量依赖性心率减慢作用；皮下注射后 smin即可起效，15刁0min达到作用峰值，90叶20min心率抑制作用趋于减弱或消失；②RWIA对大鼠左室功能具有一定的抑制作用，用药15刁0min达到作用高峰，60min抑制作用减弱，心功能开始恢复；③RWIA对左室收缩压有短暂性降低作用，用药3（hat后即可恢复正常；④R－－PIA对左室功能抑制的同时，也可明显降低心肌耗氧量指标RPP，而且对后者的作用更为持久。Q）第H部分：①心肌梗死范围：R－－PIA组心肌梗死范围显著低于生理盐水组及＊于n州＊CPX组（尸均狈．o门；卜PIA＋L－NNA组与RWIA组比较无显著性差异（NO．05）；RWIA嘴列苯职组心肌梗死范围显著低于生理盐水组（HO．01），但高于RWIA 组 （HO．01）。鳅血性室性心律失常发生率：RWIA组室速和室颤的发生率均显著低于生理盐水组、R－－PIA＋DPCPX组和RWIA＋格列苯腺组 炉均狈．0厂而与R－－PIA－．－－＊－－mm＊H组比较无显著性差别（HO．05）。③，0肌缺血前后心脏功能指标的变化：心肌缺血前各项左室功能指标组间差异无显著性 （HO．05）；而缺血15min各组大鼠左室士加川t。、LVroP、RPP与缺血前比较均有所降低，但生理盐水组与RWIA组、R－－PIA＋L删组及RWIA＋格列苯腺组比较下降更为明显（尸均叨．05）；在缺血30min，RWIA组上述指标较缺血 15min有所回升，其中士dP川tt。和 RPP，RWIA组与生理盐水组和 RWIA＋DPCPX组比较回升更为显著（尸均狈．01）；④心肌细胞凋亡：RWIA用药24小时，·心肌缺血再灌注后，生理盐水组、R－PIA组及RPIA＋DPCPX组梗死周围心肌凋亡细胞计数组间差异无显著性（HO．05）；⑤心肌NF一。B结合活性：凝胶电泳迁移率变动分析（EMSA）结果表明，RWIA组大鼠缺血再灌注后心肌 NF K B结合活性比生理盐水组和 RpIA＋DPCPX组 3 中国人民解放军军医进修学院 博士学位论文明显增强；而生理盐水组和RWIA＋DPCPX组比较，缺血再灌注后心肌NF－KB结合活性变化不明显。 结论 ＊）第一部分：①再次验证了腺营A；受体激动剂RWIA对正常麻醉大鼠具有剂量依赖性的心率减慢作用；②初次揭示了腺昔A；受体介导的负性肌力作用和心肌需氧量降低的不同步性，亦即后者更为持久。这可能更有利于腺昔类药物对缺血心肌的保护作用；③大鼠皮下注射R－－P IA方法简便、吸收迅速、重复性好，有利于进行R－PIA的一般药理学试验。u）第H部分：①腺昔A；受体激动剂RWIA 0．03mg儿g皮下注射24h后，可使大鼠心脏产生延迟预适应作用，即显著降低心肌梗死范围、减少缺血性室性心律失常（室速和室颤）和保护缺血期左室功能；②一氧化氮可能在腺昔Al受体介导的大鼠延迟预适应的触发机制中不起主要作用；铆TP敏感性钾通道可能部分参与了大鼠心肌延迟预适应；④RWIA药理性延迟预适应可能不具有抗心肌细胞凋亡作用；⑤NF－。B的活化可能在R－PIA延迟预适应的信号转导机制中具有一定作用。更多还原

【Abstract】 Objectives: (1)Part one: To determine the regulative effects of adenosineA~1 receptor agonist R-phenylisopropyladenosine(R-PIA) on the heat rate(HR)and the cardiac function in rats. (2) Part two: To investigate whether R-PIAcould induce delayed myocardial protection of pharmacological preconditioningand to investigate the role of nitric oxide Synhase (NOS), ATP-sensitivepotassium channel (K~ATP) and myocardial nuclear facor-kappa B (NF-kB) indelayed cardioprotection of R-PIA, so as to obtain some evidences on clinicalvalue of R-PIA in cardioprotection.Methods: (1) Part one: Forty male Wistar rats were randomly divided intofive groups (8 rats for each ): Group normal saline, Group R-PIA 0.03mg/kg,Group R-PIA 0.04mg/kg, Group R-PIA 0.05mg/kg; Group R-PIA 0.03mg/kg plusDPCPX (an adenosine A~1 receptor antagonist ) 0.2mg/kg. After beinganesthetized, rats were inserted plastic cannula into left ventricular (LV) caviythrough carotid artery,and the hemodynamics indexes of LV were continuouslymonitored and processed by Cardio2 pressure sisnal processing software. Atdifferent point before and after Subcutaneous administration of the trugs, theparameters of HR, LV-PSP, LV-DP±dp/dt~max、(the maximum ofshortening velocity of myocardium under unloading ) and RPP were recorded.The data wer Processed by SPSS 8.0 statistics analysis software.(2) Part two: Eighty male Wistar rats were randomly divided into five groups(l6 rats for each ): Group normal saline, Group R-PIA; Group R-PIA plusDPCPX, Group R-PIA plus L-NNA (a nitrogen monoxide synthase inhibitor );Group R-PIA plus Gli (an inhibitor of ATP sensitive potassium channel ). Ratswer fed as usual for 24 hours after subcutaneous administration of drugs andinserted plastic cannula into LV cavity through carotid artery after anesthesia.LV pressure curve, HR and heart rhythm were continually monitored andanalyzed by Cardio2 software. Electrocardiography was recorded by multiplephysiological signals recorder. Rats underwent 30 min of regional myocardialischemia followed by l20 min of reperfusion, and then the hearts werefarvested for infarct size determination (TTC stain) in 8 rats each group. LVmyocardial samples in the other 8 rats each group were obtained. A half of eachsample was frozen immediately in liquid nitrogen and then stored at-70℃ forassessment of myocardial nuclear factor -kappa B(NF-kB) binding activitys(eleCtrophootic mobility shift assay), and the other half of each sample wasfixed in 4% parafOrmaldehyde solUtion for dotednation of myOcardial cellsaPoPtosis in sfor tissue seCtion (oc assay). The daa wer Processed bySPSS 8.0 stallStics analysis sobo.ReSultS: (1) Part one: @ A dose-dePenden negatbo chronotrPic effect onthe heart was PrOduced by RM in anasthatised rats, The decrease of HR wasStarted frOm 5 mn aller RPIA SUbCUtaneos injeCtion and got the loweSt vafueduring l5~30 ndn affer adndulstfallon of RPIA. The the of R4IA on HR~aily lishenat ana disavnearea atrins 90-l20 dri. @ m temnoopinhibition of LV funCtion induced by RPIA Wen to mbomum during l5-30 ninand tended to weaken at 60 ndn aller adchstration of the drug. @ The LVPSP was teInPorarily lowerd by R4IA subcutaneos injeCtion and this effecttended to vhash at 30 ndn aller adIninistration of it. @ The RPP, an indexrefleCting myocardial Oxygen requirement, was significanly reduced by RPIAttis effat of RPIA on the RPP cOuld laSt for a longer time than on the inhibitionof LV funotion.(2) Part tWo: O The myocardial infarction size (MIS) in grouP R4IAwas sighficanly less than thOse in grou nonnal Saine and grou RWIA plusDPCPX (P all <0.0l), Ther was no sigulfican differnce in MIS betWen grouPRPIA pIus L-NNA and grOU R4IAop.05), The MIS in grou RPIA plus Giwas signifiCanly 1ess than that in grou nOnnal saline (P<0.0l), bu ~ficantlymore than tha in grou RM ew.05). @ DUring myocardial ischenda, theincidences of bOth Ventricular taChycardia (VT) and ven更多还原