Aged rat myocardium exhibits normal adenosine receptor-mediated bradycardia and coronary vasodilation but increased adenosine agonist-mediated cardioprotection.
Aged rat myocardium exhibits normal adenosine receptor-mediated bradycardia and coronary vasodilation but increased adenosine agonist-mediated cardioprotection.
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老年大鼠心肌表现出正常的腺苷受体介导的心动过缓和冠状血管舒张，但腺苷激动剂介导的心脏保护作用增加。
DOI：
10.1093/gerona/60.11.1399
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Lasley,RobertD
中科院分区：
文献类型：
--
作者：
Kristo,Gentian;Yoshimura,Yukihiro;Keith,ByronJ;MentzerJr,RobertM;Lasley,RobertD
The purpose of this study was to determine whether aged myocardium exhibits decreased responsiveness to adenosine A1and A2areceptor activation. Studies were conducted in adult (4–6 months) and aged (24–26 months) Fischer 344 × Brown Norway hybrid (F344 × BN) rats. Effects of the adenosine A1/A2aagonist AMP579 were measured in isolated hearts and in rats submitted to in vivo regional myocardial ischemia. Aged isolated hearts exhibited lower spontaneous heart rates and higher coronary resistance, as well as normal A1- and A2a-mediated responses. There was no difference in control infarct size between adult and aged rats; however, AMP579 treatment resulted in a 50% greater infarct size reduction in aged rats (18 ± 4% of risk area) compared to adult rats (37 ± 3%). These findings suggest that adenosine A1and A2areceptor-mediated effects are not diminished in normal aged myocardium, and that aged hearts exhibit increased adenosine agonist-induced infarct reduction.
