阿霉素对实验兔心肌细胞内游离钙和肌浆网Ca2+-ATP酶活性的影响

目的：探讨治疗剂量阿霉素（ADR）对心脏血流动力学及心肌肌浆网Ca^2 －ATP酶活性的影响。方法：实验兔每周静脉注射ADR（2mg/kg）1次，共8周，以健康同龄兔静脉注射等量生理盐水为对照组。这药3周后多普勒测定降主动脉血流量，以代表心输出量（CO），左颈总动脉和左心室插管测定血压（BP），平均动脉压（MAP），左心室收缩压（LVSP），左心室舒张末压（LVEDP）。应用荧光分光光度计测定心肌细胞内游离钙（MyoCa^2 ）浓度，无机磷酸根法测定心肌肌浆网（SR）Ca^2 －ATP酶活性。结果：阿霉素组CO、BP、MAP、LVSP均较对照组低，而VEDP则明显增高。阿霉素组使MyoCa^2 浓度显著增高，同时SR Ca^2 -ATP酶活性明显低于对照组。结论：治疗剂量阿霉素可使心脏功能下降，心肌细胞内钙超载及SR Ca^2 －ATP酶活性降低。

Effect of adriamycin on sarcoplasmic reticulum Ca2+-ATPase activity in cardiomyocyte of rabbits

Objective: To evaluate influences of regular dose of adriamycin (ADR) on heart function and sarcoplasmic reticulum (SR) Ca 2+ ATPase in cardiomyocyte of rabbits. Methods: Nine rabbits received intraveneous injection of ADR (2 mg/kg) once a week for 8 weeks,the rabbits injected with saline were used as control group.Cardiac output (CO),blood pressure (BP),mean artery pressure (MAP),left ventricular systolic pressure (LVSP),left ventricular end diastolic pressure (LVEDP), calcium in cardiomyocyte (MyoCa 2+ ) of rabbits and SR Ca 2+ ATPase activity were examinated 3 weeks after the final injection. Results: CO,LVSP and SR Ca 2+ ATPase activity were significantly decreased in ADR treated group compared with the control group.Conversely,LVEDP and MyoCa 2+ were significantly increased in ADR treated rabbits.Conclusion: Heart function can be decreased by regular dose of ADR injection.Calcium overload in cardiomyocyte and decrease of SR Ca 2+ ATPase activity is important physiopathologic mechanism in ADR induced impairment of heart.