大鼠心肌缺血再灌注损伤时细胞核游离钙浓度的变化  

Changes of nuclear free calcium concentrations after myocardial ischemia/reperfusion injury in rats

作　　者：唐维平[1] 司良毅[2] 张乐之[1] 周红[1] 何华美[1] 

机构地区：[1]第三军医大学基础医学部药理学教研室 [2]第三军医大学西南医院老年病科,重庆400038

出　　处：《第三军医大学学报》2005年第2期112-114,共3页Journal of Third Military Medical University

基　　金：国家自然科学基金资助项目 ( 30 10 0 0 70 )~~

摘　　要：目的　探讨大鼠心肌缺血再灌注损伤 (ischemia/reperfusioninjury ,IRI)时细胞核游离钙浓度的改变。方法　健康雄性Wistar大鼠随机分为IRI组和假手术组 ,结扎冠状动脉左主干制备IRI模型 ,双波长荧光分光光度法测定分离的心肌细胞核游离钙浓度 [Ca2 + ] n。结果　核外ATP为 10mmol/L时 ,假手术组和IRI心肌 [Ca2 + ] n 均随核外钙浓度增加而增加 ;当核外游离钙为 0 1μmol/L时 ,两组心肌 [Ca2 + ] n 无差别 (P >0 0 5 ) ;当核外游离钙为 1μmol/L和 10 μmol/L时 ,IRI组[Ca2 + ] n 明显高于假手术组 (P <0 0 1)。在核外无ATP时 ,两组心肌 [Ca2 + ] n 在核外无钙时无差别 (P >0 0 5 ) ,核外游离钙在 0 4～ 1 6μmol/L时两组心肌 [Ca2 + ] n 均较在不含钙缓冲液中增加 ,但假手术组心肌 [Ca2 + ] n 在此范围内相对稳定 ,而IRI组心肌 [Ca2 + ] n 在核外游离钙浓度为 1 6μmol/L时则明显增加 (P <0 0 5 )。 结论　在核外有或无ATP时过高的核外钙浓度均引起IRI组心肌细胞核游离钙的急剧增加。Objective To study the alterations in nuclear free calcium concentrations after myocardial ischemia/reperfusion injury (IRI) in rats. Methods Healthy male Wistar rats were divided randomly into IRI and Sham groups. Myocardial IRI models were established by ligating the left coronary artery for 30 min and then reperfusing the hearts for 3 h. Myocardial nuclei were isolated by sucrose density gradient centrifugation and the intranuclear free calcium concentrations ([Ca 2+] n) were measured with fura-2 AM by dual-wavelength fluorophotometry. Results In the presence of 10 mmol/L ATP, [Ca 2+] n in the myocardial nuclei in both Sham and IRI groups increased as the calcium concentration in incubation buffer increased. When myocardial nuclei were incubated with calcium at the concentration of 0.1 μmol/L, [Ca 2+] n in the two groups showed no difference (P>0.05). However, when the calcium concentration in incubation buffer was 1 μmol/L or 10 μmol/L, [Ca 2+] n in IRI group was much higher than that in Sham group (P<0.01). In the absence of ATP, no difference in [Ca 2+] n in the myocardial nuclei in the calcium-free incubation buffer was observed between IRI and Sham groups (P>0.05). However, increased [Ca 2+] n was measured in the myocardial nuclei in the buffer containing calcium ranging within 0.4-1.6 μmol/L in both IRI and Sham groups. [Ca 2+] n in the myocardial nuclei in sham group remained unchanged while [Ca 2+] n in the myocardial nuclei in IRI increased when incubated in the buffer containing 1.6 μmol/L calcium (P<0.05). Conclusion In the presence or absence of ATP in the incubation buffer, nuclear free calcium concentration increases drastically in ischemic/reperfused myocardium in response to excessive calcium in the incubation buffer.

关 键 词：缺血/再灌注损伤 细胞核 心脏 钙 

分 类 号：R322.11[医药卫生—人体解剖和组织胚胎学] R329.26[医药卫生—基础医学]