Dependence of electrical slow waves of canine colonic smooth muscle on calcium gradient.
Dependence of electrical slow waves of canine colonic smooth muscle on calcium gradient.
复制标题
犬结肠平滑肌电慢波对钙梯度的依赖性。
DOI：
10.1113/jphysiol.1992.sp019303
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Sanders,KM
中科院分区：
文献类型：
--
作者：
Ward,SM;Sanders,KM
1.本文研究了犬结肠环行肌慢波上行成分和平台成分的离子依赖性。2.细胞外Ca 2+的减少引起的upstroke和高原组件的振幅，在去极化速度的减少，和频率的减少。每减少10倍的外部Ca 2+在上冲程阶段的减少接近能斯特关系预测的值，这表明膜对Ca 2+的渗透性在此阶段急剧增加。3.硝苯地平（10（-9）-10（-6））减少了平台成分，但10（-6）M的浓度并没有消除上冲程成分。这些数据表明，钙电流的硝苯地平抵抗成分可能参与了上行。4.无机钙通道阻断剂（Mn 2+和Ni 2+）在1.0mM或更低浓度下阻断自发慢波。上行程组分对Ni 2+比对Mn 2+更敏感; 0.040 mM-Ni 2+的浓度导致上行程速度降低50%以上。Ni ~（2+）也使慢波的平台期缩短。6.结果表明，慢波的上升和平台成分取决于电压依赖性Ca 2+电流的激活。负责上升冲程的电流对二氢吡啶部分耐药（至少在10（-6）M）。负责平台组分的电流是硝苯地平敏感的。
1. The ionic dependence of the upstroke and plateau components of slow waves of canine colonic circular muscles was studied. 2. Reduced extracellular Ca2+ caused a decrease in the amplitude of the upstroke and plateau components, a decrease in the depolarization velocity, and a decrease in frequency. The reduction in the upstroke phase per 10‐fold reduction in external Ca2+ was close to the value predicted by the Nernst relationship, suggesting that the membrane permeability to Ca2+ increases steeply during this phase. 3. Nifedipine (10(‐9)‐10(‐6)) reduced the plateau component, but concentrations of 10(‐6) M did not abolish the upstroke component. The data suggest that a nifedipine‐resistant component of Ca2+ current may be involved in the upstroke. 4. Inorganic Ca2+ channel blockers (Mn2+ and Ni2+) blocked spontaneous slow waves at concentrations of 1.0 mM or less. 5. The upstroke component was more sensitive to Ni2+ than to Mn2+; a concentration of 0.040 mM‐Ni2+ caused more than a 50% reduction in upstroke velocity. Ni2+ also reduced the plateau phase of slow waves. 6. The results suggest that the upstroke and plateau components of slow waves are dependent upon activation of voltage‐dependent Ca2+ currents. The current responsible for the upstroke is partially resistant to dihydropyridines (at least at 10(‐6) M). The current responsible for the plateau component is nifedipine‐sensitive.
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DOI：
10.1113/jphysiol.1985.sp015793
发表时间：
1985
期刊：
The Journal of physiology
影响因子：
--
作者：
Bauer,AJ;Reed,JB;Sanders,KM
通讯作者：
Sanders,KM
DOI：
10.1152/ajpgi.1990.259.2.g264
发表时间：
1990
期刊：
The American journal of physiology
影响因子：
--
作者：
Ward,SM;Sanders,KM
通讯作者：
Sanders,KM
影响因子：
5.5
作者：
BARAJASLOPEZ, C;DENHERTOG, A;HUIZINGA, JD
通讯作者：
HUIZINGA, JD
哇巴因对犬结肠肌细胞背景和电压依赖性电流的影响。
DOI：
10.1152/ajpcell.1990.259.3.c402
发表时间：
1990
期刊：
The American journal of physiology
影响因子：
--
作者：
Burke,EP;Sanders,KM
通讯作者：
Sanders,KM
二氢吡啶对单一钙通道的抑制作用和兔肠系膜动脉的收缩取决于电压。
DOI：
--
发表时间：
1989
期刊：
Journal of Physiology
影响因子：
--
作者：
M. Nelson;J. Worley
通讯作者：
J. Worley