Β_2肾上腺素受体拮抗剂对大鼠心肌梗死后心肌细胞胞浆游离CA^(2+)浓度的影响  

Effects of beta2-adrenergic blocker on cytosolic Ca^(2+) in isolated cardiomyocytes of rats with myocardial infarction

作　　者：杨蕙[1] 伍卫[1] 方昶[1] 邓春玉[2] 张燕[1] 

机构地区：[1]中山大学附属第二医院心内科,广东广州510120 [2]广东省心血管病研究所,广东广州510080

出　　处：《中国病理生理杂志》2005年第12期2346-2349,共4页Chinese Journal of Pathophysiology

基　　金：广州市科技攻关引导项目(2004)

摘　　要：目的:观察Β2肾上腺素受体拮抗剂对心肌梗死后心肌细胞胞浆游离CA2+浓度([CA2+]I)的影响。方法:结扎冠状动脉,复制大鼠心肌梗死模型。随机分为心肌梗死后2、4、8周组,正常对照组作假手术。分离大鼠心肌细胞,每组大鼠制备20份样品,再随机分为4小组,分别给予Β2受体拮抗剂ICI118,551、Β1受体拮抗剂阿替洛尔、非选择性Β受体拮抗剂普萘洛尔后,用FURA-2荧光技术测定心肌细胞[C2+]I。结果:心肌梗死后4、8周,ICI118, 551组心肌细胞[CA2+]I增幅显著低于异丙肾上腺素组(24．5％±5．7％ VS 57．8％±13．2％,P<0．01;12．2％±7．9％ VS 44．6％±11．3%, P<0．01);正常对照组和心肌梗死后2周,上述两组心肌细胞[CA2+]I增幅无显著差异(P> 0．05)。正常对照组和心肌梗死后2周,阿替洛尔组心肌细胞[CA2+]I增幅显著低于异丙肾上腺素组(P<0．05);正常对照组及心肌梗死后2、4、8周,普萘洛尔组心肌细胞[CA2+]I增幅均显著低于异丙肾上腺素组(P<0．05)。结论:Β2 受体拮抗剂对于有效抑制心肌梗死后交感神经激动引起的心肌细胞内钙超载可能起重要作用。AIM： To investigate if beta2- adrenergic receptors result in more Ca^2＋ load after myocardial infarction （MI）, the effects of beta2- adrenergic blocker on cytosolic Ca^2＋ （[Ca^2＋ ]i） were studied. METHODS： Male Wistar rats underwent a ligation of left coronary artery. （ n = 9） or a sham operation （ n = 3）. Cardiomyocytes were dissociated at 2, 4 and 8 weeks after MI and [Ca^2＋ ]i was measured via fura- 2 fluorescence. The response of cardiomyocytes to isoproterenol （ 1 μmol/L） in the presence or absence of atenolol （1 μmol/L）, beta2- adrenergic blocker IC1118,551 （0.1 μmol/L） or propranolol （1 μmol/L） was examined. RESULTS： IC1118, 551 suppressed the increase in [ Ca^2＋ ] i induced by isoproterenol at 4 and 8 weeks after MI （24.5% ± 5.7% vs 57.8% ± 13.2%, P 〈 0.01; 12.2% ± 7.9% vs 44.6% ± 11.3%, P 〈 0.01）, but had no effects in control and 2 weeks post- MI groups. It decreased [Ca^2＋ ]i in control and the three post- MI groups by 14.3%, 7.9%, 57.6% and 72.6%, respectively. Atenolol had suppressive effects only in control and 2 weeks post- MI groups （P 〈 0.05）. Propranolol had suppressive effects in control and all three post - MI groups （ P 〈 0.01 ）. CONCLUSION： Beta 2 - adrenergic blocker IC1118,551 exerts negative effects on [ Ca^2 ＋ ]i after M1, and tBe effects dramatically increase with the progression of MI.

关 键 词：受体 肾上腺素能β2 肾上腺素能β受体拈抗剂 心肌梗死 钙 

分 类 号：R541.6[医药卫生—心血管疾病]