Properties of the hyperpolarization-activated current (If) in isolated mouse sino-atrial cells
Properties of the hyperpolarization-activated current (If) in isolated mouse sino-atrial cells
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DOI：
10.1016/s0008-6363(01)00370-4
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发表时间：
2001-10-01
影响因子：
10.8
通讯作者：
Nargeot, J
中科院分区：
文献类型：
--
作者：
Mangoni, ME;Nargeot, J
目的：我们研究了小鼠窦房结 (SAN) 起搏细胞中超极化激活 (I-t) 电流的特性。方法：在从成年 C57BL6/J 小鼠 SAN 区域酶促分离的细胞中研究 I-f 电流。采用膜片钳技术的全细胞变异来研究 I-f 的基本特性。结果：在小鼠 SAN 细胞中，-120 mV 时的 I-f 电流密度为 18 +/-2 pA/pF (n=23)。 1，在 SAN 制剂中也发现的心房样形态的细胞中未检测到 (n=7)。 I-f被5mM Cs'阻断，被5μM乙酰胆碱抑制，并被10μM去甲肾上腺素增加。 1、在Na+和K+离子的生理浓度下，电流反转电位为-31+/-2mV。降低细胞外Na+浓度会降低If振幅，而当细胞外K+浓度增加时则增加。半激活的 I-f 电压为 -87 +/-1 mV (n=6)。结论：我们得出结论，小鼠 SAN 细胞中的天然 I-f 电流显示出与兔 SAN 组织中描述的 If 相似的功能特性。这项研究开启了研究 I-f 在转基因小鼠心率调节中的作用的可能性。 (C) 2001 Elsevier Science B.V. 保留所有权利。
Objective: We have investigated the properties of the hyperpolarization-activated (I-t) current in pacemaker cells from the mouse sino-atrial node (SAN). Methods: The I-f current was studied in cells isolated enzymatically from the SAN region of adult C57BL6/J mice. The whole-cell variation of the patch-clamp technique was employed to investigate the basic properties of I-f. Results: In mouse SAN cells, the I-f current density at -120 mV was 18 +/-2 pA/pF (n=23). 1, was not detected in cells showing atrial-like morphology that were also found in SAN preparations (n=7). I-f was blocked by 5 mM Cs', was inhibited by application of 5 muM acetylcholine, and was increased by 10 muM noradrenaline. The 1, current reversal potential was -31 +/-2 mV under physiological concentration of Na+ and K+ ions. Lowering the extracellular Na+ concentration reduced If amplitude, while increased when the extracellular K+ concentration was augmented. I-f voltage for half activation was -87 +/-1 mV (n=6). Conclusions: We conclude that the native I-f current in mouse SAN cells shows functional properties that are similar to If described in rabbit SAN tissue. This study opens the possibility of investigating the involvement of I-f in the regulation of heart rate in genetically modified mice. (C) 2001 Elsevier Science B.V. All rights reserved.