CGP37157对静息期心肌细胞钙循环的影响

目的：研究离子通道阻断剂CGP37157对成年大鼠静息期心肌细胞钙循环的影响。方法：（1）32只雄性SD大鼠随机等分为4组,用于测定心肌组织中cAMP的含量。对照组不灌流CGP37157,实验组分3个时间梯度：用10μmol/L CGP37157灌流心脏15 min、30 min和60 min;（2）20只雄性SD大鼠随机均分为两组,对照组和实验组（细胞池中加入10μmol/L CGP37157）采用常规酶解法分离心肌细胞,激光扫描共聚焦显微镜记录钙瞬变;利用SPSS11.5统计软件进行数据处理,所有数据以均数±标准差（x珋±SD）表示,两组间均数的比较采用t检验。P〈0.05为差异有统计学意义。结果：（1）心肌组织中cAMP含量的比较：CGP37157引起心肌组织cAMP的含量显著增加（n=8,P〈0.05）,对照组、15 min、30 min和60 min各组测得的cAMP的含量分别为（791±35）pmol/g、（1 101±55）pmol/g、（1 525±40）pmol/g、（2 017±60）pmol/g;60 min组较30 min组cAMP含量显著增加（n=8,P〈0.05）;（2）对静息期肌浆网钙循环的影响：实验组钙存储改变量（20.2±0.8）显著高于对照组（0.3±0.3;n=10,P〈0.01）;实验组钙释放速率变化（5.02±0.015）比对照组显著增大（1.01±0.006;n=10,P〈0.01）;实验组钙回摄速率变化（1.08±0.15）与对照组没有差异（0.99±0.09;n=10,P〉0.05）。结论：CGP37157导致静息期心肌细胞钙循环的异常,原因可能为其导致PKA通路异常。

The effect of CGP37157 on diastolic myocardial calcium cycling

Objective：Study the effect of CGP37157 on diastolic myocardial calcium cycling.Methods：（1） 32 male SD rats were randomly and equally divided into four groups： control group（without CGP37157）,experiment groups with 10 μmol/L CGP37157 for 15min,30min and 60min,respectively.cAMP content in cardiac tissue was measured;（2） 20 male SD rats were randomly and equally divided into two groups： control group（without CGP37157） and experiment group（with 10 μmol/L CGP37157）.Single cardiomyocytes of the rat heart were isolated by an enzymatic dissociation method and laser scanning confocal microscope was used to record intracellular Ca2＋ transients.SPSS11.5 software was used for statistical analysis.All the data were presented as mean±SD,and t-test was used for the statistical analysis.P-values of 0.05 was considered significant.Results：（1） cAMP content in experiment groups（1 101±55）pmol/g,（1 525±40）pmol/g,（2 017±60）pmol/g was increased compared with control group（791±35）pmol/g;（n=8,P0.05）,respectively;cAMP content of 60 min group was increased compared with that of 30min group（n=8,P0.05）;（2） Diastolic calcium cycling in cardiac myocytes： the change of calcium storage was increased in experiment group（20.2±0.8） compared with control group（0.3±0.3,n=10,P0.01）;the rate of calcium release was increased in experiment group（5.02±0.015） compared with control group（1.01±0.006,n=10,P0.01）;the rate of calcium uptake（1.08±0.15 vs 0.99±0.09,n=10,P0.05） failed to alter in experiment group compared with control group.Conclusion：The present results suggest that CGP37157 results in abnormal cardiac calcium cycling,and this is associated with abnormal PKA pathway.