Ca2+ cycling in heart cells from ground squirrels: adaptive strategies for intracellular Ca2+ homeostasis.
Ca2+ cycling in heart cells from ground squirrels: adaptive strategies for intracellular Ca2+ homeostasis.
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DOI：
10.1371/journal.pone.0024787
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Wang SQ
中科院分区：
文献类型：
--
作者：
Li XC;Wei L;Zhang GQ;Bai ZL;Hu YY;Zhou P;Bai SH;Chai Z;Lakatta EG;Hao XM;Wang SQ
冬眠哺乳动物（例如地松鼠）的心脏组织能够承受低温、缺氧和其他对人类和非冬眠哺乳动物致命的极端伤害因素。本研究旨在了解与大鼠相比，哺乳动物冬眠者地松鼠心肌细胞内 Ca2+ 稳态的适应性机制。电生理学和共焦成像实验表明，与大鼠相比，地松鼠心室肌细胞中 L 型 Ca2+ 电流 (I Ca) 的电压依赖性转变为更高的电位。 I Ca 阈值的升高并不影响 Ca2+ 诱导的 Ca2+ 释放，因为较高的去极化率和较长的动作电位持续时间补偿了 I Ca 的电压偏移。在地松鼠中，胞质 Ca2+ 去除的咖啡因敏感成分和咖啡因抗性成分均更快。与大鼠相比，地松鼠的 Ca2+ 火花表现出更大的幅度/尺寸和更低的频率。由于高 I Ca 阈值、低 SR Ca2+ 渗漏和快速的胞质 Ca2+ 清除，地松鼠的心脏细胞比大鼠和其他非冬眠哺乳动物的心脏细胞表现出更好的维持细胞内 Ca2+ 稳态的能力。这些发现不仅揭示了冬眠的适应性机制，而且还提供了针对 Ca2+ 超载相关心脏病的新策略。
Heart tissues from hibernating mammals, such as ground squirrels, are able to endure hypothermia, hypoxia and other extreme insulting factors that are fatal for human and nonhibernating mammals. This study was designed to understand adaptive mechanisms involved in intracellular Ca2+ homeostasis in cardiomyocytes from the mammalian hibernator, ground squirrel, compared to rat. Electrophysiological and confocal imaging experiments showed that the voltage-dependence of L-type Ca2+ current (I Ca) was shifted to higher potentials in ventricular myocytes from ground squirrels vs. rats. The elevated threshold of I Ca did not compromise the Ca2+-induced Ca2+ release, because a higher depolarization rate and a longer duration of action potential compensated the voltage shift of I Ca. Both the caffeine-sensitive and caffeine-resistant components of cytosolic Ca2+ removal were more rapid in ground squirrels. Ca2+ sparks in ground squirrels exhibited larger amplitude/size and much lower frequency than in rats. Due to the high I Ca threshold, low SR Ca2+ leak and rapid cytosolic Ca2+ clearance, heart cells from ground squirrels exhibited better capability in maintaining intracellular Ca2+ homeostasis than those from rats and other nonhibernating mammals. These findings not only reveal adaptive mechanisms of hibernation, but also provide novel strategies against Ca2+ overload-related heart diseases.
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影响因子：
--
作者：
KAMM, KE;ZATZMAN, ML;SOUTH, FE
通讯作者：
SOUTH, FE
影响因子：
56.9
作者：
LOPEZLOPEZ, JR;SHACKLOCK, PS;WIER, WG
通讯作者：
WIER, WG
影响因子：
56.9
作者：
CHENG, H;LEDERER, WJ;CANNELL, MB
通讯作者：
CANNELL, MB
影响因子：
37.8
作者：
Hara, A;Yuhki, K;Ushikubi, F
通讯作者：
Ushikubi, F
影响因子：
56.9
作者：
KONDO, N;SHIBATA, S
通讯作者：
SHIBATA, S