Effects of erythrocyte lysate of different incubation times on intracellular free calcium in rat basilar artery smooth-muscle cells.
Effects of erythrocyte lysate of different incubation times on intracellular free calcium in rat basilar artery smooth-muscle cells.
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DOI：
10.3171/jns.1998.89.6.1007
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发表时间：
1998-12
影响因子：
4.1
通讯作者：
Y. Guan;B. Weir;L. Marton;R. Macdonald;H. Zhang
中科院分区：
文献类型：
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作者：
Y. Guan;B. Weir;L. Marton;R. Macdonald;H. Zhang
目的探讨红细胞内物质(S)对血管痉挛发病机制的影响。方法由于蛛网膜下腔出血(SAH)后血管痉挛的发生，作者研究了老年人红细胞溶血物及其低分子量(LMW)和高分子量(HMW)组分对新鲜分离的大鼠基底动脉平滑肌细胞[Ca++]i的影响。新鲜溶血液(第0天)产生一个由瞬时峰值和持续的[Ca++]i升高组成的双时相反应，而孵育3、7或14天的细胞制备的溶血液只引起一过性反应，没有持续时相。随着孵育时间的延长，溶血液的作用逐渐减弱。HMW组分和纯化的人氧合血红蛋白(OxyHb)没有引起反应。从第3、7或14天开始的LMW组分在低浓度(20%)下没有反应，并且随着孵育时间的增加，这种影响减弱。未分离的溶血液或低分子量组分的溶血液孵育21天后无反应。从第3天开始的10%的LMW组分与10%的HMW组分(3.7、14或21天)的组合瞬时增加了[Ca++]i。然而，从第14天开始的10%LMW组分和从第3天或第14天开始的10%HMW组分对[Ca++]i没有影响。在OxyHb存在的情况下，在第3天和第7天，[Ca++]i增加了10%的LMW组分，但从第14天或第21天开始，LMW组分的[Ca++]i没有增加。结论溶血液对[Ca++]i的影响随着时间的推移而下降，表明红细胞释放物质的时间在血管痉挛的发生中起重要作用，或者该实验系统不能代表SAH后的情况。这些数据表明，溶血物升高血管平滑肌细胞[Ca++]i的能力是由多种物质提供的，包括OxyHb。这些物质可能在红细胞体外孵育后的特定时间内相互作用。
OBJECT The purpose of this study was to characterize substance(s) in the erythrocytes that increase intracellular free Ca++ concentration ([Ca++]i) in smooth-muscle cells and that therefore may be involved in the pathogenesis of vasospasm. METHODS Because vasospasm occurs days after subarachnoid hemorrhage (SAH), the authors studied the effects of aged human erythrocyte hemolysate and its low-molecular-weight (LMW) and high-molecular-weight (HMW) fractions on [Ca++]i in freshly isolated rat basilar artery smooth-muscle cells. Fresh hemolysate (Day 0) produced a biphasic response consisting of a transient peak and a sustained plateau increase in [Ca++]i, whereas hemolysate prepared from cells incubated for 3, 7, or 14 days induced only a transient response without a sustained phase. The effect of hemolysate declined with increasing incubation time. The HMW fraction and purified human oxyhemoglobin (OxyHb) did not evoke a response. The LMW fraction from Days 3, 7, or 14 produced no response at low concentrations ( 20%), and the effect diminished with increasing incubation time. Unfractionated hemolysate or the LMW fraction of hemolysate incubated for 21 days produced no response. The combination of the 10% LMW fraction from Day 3 plus the 10% HMW fraction (Days 3. 7, 14, or 21) transiently increased [Ca++]i,. However, [Ca++]i was not changed by the 10% LMW fraction from Day 14 plus the 10% HMW fraction from Day 3 or 14. In the presence of OxyHb, [Ca++]i was increased by the 10% LMW fraction on Days 3 and 7, but not by the LMW fraction from Days 14 or 21. CONCLUSIONS The decline over time in the effect of hemolysate on [Ca++]i indicates either that the time that substances are released from erythrocytes is important in the generation of vasospasm or that this experimental system as used is not representative of conditions present after SAH. The data indicate that the ability to elevate [Ca++]i in smooth-muscle cells with hemolysate is provided by multiple substances, including OxyHb. These substances may interact during specific times after incubation of erythrocytes in vitro.