ROLE OF CA2+ IN MAINTENANCE OF RABBIT MYOCARDIAL-CELL MEMBRANE STRUCTURAL AND FUNCTIONAL INTEGRITY
ROLE OF CA2+ IN MAINTENANCE OF RABBIT MYOCARDIAL-CELL MEMBRANE STRUCTURAL AND FUNCTIONAL INTEGRITY
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DOI：
10.1016/0022-2828(78)90354-1
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发表时间：
1978-01-01
影响因子：
5
通讯作者：
FRANK, JS
中科院分区：
文献类型：
--
作者：
CREVEY, BJ;LANGER, GA;FRANK, JS
在离体动脉灌注兔室间隔中研究了肌膜浅层的结构和功能以及肌膜对[Ca]o的依赖性。用 O Ca (< 5 μM) 溶液进行组织灌注 20 分钟，产生膜浅层的独特分离。这些分离是不可逆的，并且与正常[Ca]o再灌注时细胞45Ca含量增加和不可逆挛缩相关。用50μM Ca灌注不产生膜结构、收缩功能或45Ca摄取的改变。零 Ca 灌注导致平均细胞 42K 损失 14%，这似乎与表面膜分离无关。 O Ca 灌注液中的 Mg 补充剂导致膜分离和挛缩，其结果与未添加补充剂的 O Ca 和 50 μM Ca 的情况处于中间状态；镁补充剂可完全防止细胞钾流失。零 [Ca] 诱导的浅层分离与 Ca 渗透性增加相关，表明该膜区域参与收缩 Ca 的控制。 Ca 离子对于控制 K 渗透性至关重要，可能在脂质双层中。 [Ca]o 的存在对于这些膜位点的正常结构和功能很重要。
The structure and function of sarcolemmal superficial layers and sarcolemmal dependence on [Ca]o was studied in isolated arterially perfused rabbit interventricular septum. Tissue perfusion for 20 min with O Ca (< 5 .mu.M) solution produced a distinctive separation of membrane superficial laminae. These separations were irreversible and associated with increased cellular 45Ca content and irreversible contracture when normal [Ca]o was reperfused. Perfusion with 50 .mu.M Ca produced no alteration of membrane structure, contractile function or 45Ca uptake. Zero Ca perfusion resulted in 14% mean cellular 42K loss which appeared independent of superficial membrane separations. Mg supplements in O Ca perfusate resulted in membrane separations and contracture intermediate to those of O Ca without supplements and 50 .mu.M Ca; Mg supplements completely protected against cellular K loss. Zero [Ca]-induced separation of superficial laminae correlates with increased Ca permeability and suggests that this membrane region is involved in control of contractile Ca. Ca ion is essential for control of K permeability, probably in the lipid bilayer. The presence of [Ca]o to the normal structure and function of these membrane sites is important.