The effects of nickel and cobalt ions on the spontaneous electrical activity, slow wave, in the circular muscle of the guinea-pig gastric antrum.
The effects of nickel and cobalt ions on the spontaneous electrical activity, slow wave, in the circular muscle of the guinea-pig gastric antrum.
复制标题
镍和钴离子对豚鼠胃窦环形肌自发电活动（慢波）的影响。
DOI：
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
K. Ogino
中科院分区：
文献类型：
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作者：
T. Tomita;Y. Pang;K. Ogino
1.豚鼠胃肌环肌条以慢波形式产生自发性电活动。慢波幅度平均为31 mV，最大上升速率平均为60 mV/s，持续时间平均为4.3 s，频率平均为4.3 m in-1。3微米硝苯地平或尼卡地平对上述参数无明显影响，即使在60 mM K+去极化后也是如此。2.Ni2+(1-100微米)增加慢波幅度和频率，但降低上升速率，并伴有膜去极化。在Ni2+的持续存在下，上升速率和去极化速率缓慢恢复到控制值，但慢波频率仍然很高。洗涤后的回收率很差，特别是当施加高浓度的Ni2+时。3.Co2+与Ni2+的作用基本相同。4.在无Ni2+和有Co2+存在的情况下，外源性钙离子的去除使慢波的上升速度和幅度缓慢降低，但在这些金属离子的存在下，这种影响有所减弱。5.大于1 mM的Ni2+和Co2+对慢波有抑制作用。然而，当在抑制过程中用N-甲基-D-氨基葡萄糖胺取代外加Na+时，几乎恢复了正常的电活动。6.由于硝苯地平(3微米)和镍离子(100微米)对慢波无明显影响，因此产生慢波的内向电流似乎不流经L型钙通道或典型的T型钙通道。慢波可能被Ni2+和Co2+作用于细胞内而增强。这些离子在较高浓度下对起搏器活动的抑制似乎比对导致慢波产生的内向电流的抑制更强。
1. Circular muscle strips of the guinea-pig gastric muscle produced spontaneous electrical activity in the form of slow waves. The slow wave amplitude, maximum rate of rise, duration, and frequency were 31 mV, 60 mV sec-1, 4.3 sec, and 4.3 min-1 on average, respectively. These parameters were not appreciably affected by 3 microM nifedipine or nicardipine, even following membrane depolarization with 60 mM K+. 2. Ni2+ (1-100 microM) increased slow wave amplitude and frequency, but reduced the rate of rise, accompanied by membrane depolarization. The rate of rise and depolarization slowly recovered to the control values in the continuous presence of Ni2+, but slow wave frequency remained high. The recovery after wash-out was very poor particularly when a high concentration of Ni2+ was applied. 3. The effects of Co2+ were fundamentally the same as those of Ni2+. 4. Removal of external Ca2+ slowly reduced the rate of rise and amplitude of the slow waves in the absence and the presence of Ni2+ and Co2+, although the effects were reduced in the presence of these metal ions. 5. Concentrations of Ni2+ and Co2+ greater than 1 mM suppressed the slow waves. However, when the external Na+ was replaced with N-methyl-D-glucamine during the suppression, nearly normal electrical activity was resumed. 6. Since slow waves were not significantly affected by nifedipine (3 microM) and Ni2+ (100 microM), the inward currents generating slow waves do not seem to flow through L-type Ca2+ channels or typical T-type Ca2+ channels. Slow waves are probably potentiated by Ni2+ and Co2+ acting intracellularly. These ions at higher concentrations seem to inhibit the pacemaker activity more powerfully than they do the inward currents responsible for slow wave generation.
犬结肠平滑肌电慢波对钙梯度的依赖性。
DOI：
10.1113/jphysiol.1992.sp019303
发表时间：
1992
期刊：
The Journal of physiology
影响因子：
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作者：
Ward,SM;Sanders,KM
通讯作者：
Sanders,KM
钴对血管平滑肌的收缩作用依赖于钙。
影响因子：
3
作者：
Gallagher,MJ;Alade,PI;Dominiczak,AF;Bohr,DF
通讯作者：
Bohr,DF