Properties of pacemaker potentials recorded from myenteric interstitial cells of Cajal distributed in the mouse small intestine
Properties of pacemaker potentials recorded from myenteric interstitial cells of Cajal distributed in the mouse small intestine
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DOI：
10.1113/jphysiol.2003.051334
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发表时间：
2003-12-15
影响因子：
5.5
通讯作者：
Suzuki, H
中科院分区：
文献类型：
--
作者：
Kito, Y;Suzuki, H
用常规微电极记录小鼠离体肠的电反应，发现有两种电位，起搏电位和慢波，均有快速上升的初级成分和随后的平台成分。起搏电位的上升率和峰值大于慢波，平台成分慢波小于起搏电位。两种电位以相似的频率振荡(20-30min(-1))。单位电位，通常在起搏器电位之间的间歇期间放电。注入荧光黄可以观察到记录的细胞；起搏电位记录于Cajal肌间质细胞(ICC-My)，慢波记录于环状平滑肌细胞。起搏电位的特征如下：初级成分被Ni2+、无钙溶液或高K+溶液去极化抑制，平台成分被钙激活的氯通道抑制剂4，4‘-二异硫氰基二苯乙烯-2，2’-二磺酸(DIDS)、低[Cl-](无穷大)溶液或无钙溶液抑制，Ni2+和DIDS共同作用或细胞内钙离子与1，2-双(2-氨基苯氧基)乙烷-N，N，N‘，N’-四乙酸乙氧甲酯(BAPTA-AM)螯合可抑制起搏电位的产生。这些结果表明，在小鼠小肠，ICC-MY产生的起搏电位具有两种成分，初级成分和平台成分可能分别通过激活电压依赖性钙离子通透通道和钙离子激活的氯离子通道而产生。慢波是通过起搏电位的电紧张性传播在环形平滑肌肉中产生的。肠起搏电位的这些特性被认为与胃起搏电位的这些特性基本相似。
Recording of electrical responses from isolated small intestine of mice using conventional microelectrodes revealed two types of potential, a pacemaker potential and a slow wave, both with rapid rising primary components and following plateau components. The rate of rise and peak amplitude were greater for pacemaker potentials than for slow waves, and the plateau component was smaller in slow waves than in pacemaker potentials. Both potentials oscillated at a similar frequency (20-30 min(-1)). Unitary potentials often discharged during the interval between pacemaker potentials. Infusion of Lucifer Yellow allowed visualization of the recorded cells; pacemaker potentials were recorded from myenteric interstitial cells of Cajal (ICC-MY) while slow waves were recorded from circular smooth muscle cells. Pacemaker potentials were characterized as follows: the primary component was inhibited by Ni2+, Ca2+-free solution or depolarization with high-K+ solution, the plateau component was inhibited by 4,4'-diisothiocyanostilbene-2,2'-disulphonic acid (DIDS), an inhibitor of Ca2+-activated Cl- channels, low [Cl-](infinity) solution or Ca2+-free Solution, and the generation of potentials was abolished by co-application of Ni2+ and DIDS or by chelating intracellular Ca2+ with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM). These results indicate that in the mouse small intestine ICC-MY generate pacemaker potentials with two components in situ; the primary and plateau components may be generated by activation of voltage-dependent Ca2+-permeable channels and Ca2+-activated Cl- channels, respectively. Slow waves are generated in circular smooth muscles via electrotonic spread of pacemaker potentials. These properties of intestinal pacemaker potentials are considered essentially similar to those of gastric pacemaker potentials.