Effects of flavoxate hydrochloride on voltage-dependent Ba2+ currents in human detrusor myocytes at different experimental temperatures
Effects of flavoxate hydrochloride on voltage-dependent Ba2+ currents in human detrusor myocytes at different experimental temperatures
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不同实验温度下盐酸黄酮酯对人逼尿肌细胞电压依赖性Ba2电流的影响
DOI：
10.1007/s00210-007-0190-6
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
N. Teramoto
中科院分区：
文献类型：
--
作者：
T. Tomoda;Hai‐Lei Zhu;K. Iwasa;M. Aishima;Atsushi Shibata;N. Seki;S. Naito;N. Teramoto
采用全细胞膜片钳技术研究了不同温度下盐酸黄酮哌酯（piperidinoethyl-3-methylflavone-8-carboxylate，以下简称flavoxate）对人逼尿肌细胞电压依赖性硝苯地平敏感性内向Ba ~（2+）电流（IBa）的抑制作用。当浴-溶液温度从22°C增加到30°C时，在若干测试电位下IBa峰振幅增强约两倍。IBa阈值和IBa最大峰幅度的膜电位均不受温度变化的影响。与22°C（Ki = 10.3 μM）相比，30°C（Ki = 5.1 μM）和37°C（Ki = 4.6 μM）下的浓度-反应曲线略微左移。在硝苯地平的存在下也获得了类似的结果（Ki = 14 nM，22°C; Ki = 2.5 nM，30°C; Ki = 2.1 nM，37°C）。将水浴温度从22°C改变到30°C，IBa在−90 mV的稳态失活曲线向左移动。在30°C下，与不存在flavoxate相比，存在flavoxate时IBa的稳态失活曲线也向左移动。3-异丁基-1-甲基黄嘌呤（IBMX）或茶碱（磷酸二酯酶抑制剂）对IBa的影响很小，尽管环核苷酸（二丁酰cAMP和8-Br-cGMP）抑制IBa。这些结果表明，在不同的实验温度下，flavoxate对人逼尿肌细胞IBa的抑制作用略有变化，flavoxate直接阻断电压依赖性L-型Ca ~（2+）通道，而不是通过抑制磷酸二酯酶活性途径。
The inhibitory effects of flavoxate hydrochloride (piperidinoethyl-3-methylflavone-8-carboxylate; hereafter referred as flavoxate) on voltage-dependent nifedipine-sensitive inward Ba2+ currents (IBa) in human detrusor myocytes were investigated at different temperatures using conventional whole-cell patch-clamp techniques. When the bath-solution temperature was increased from 22°C to 30°C, IBa peak amplitude was enhanced by approximately twice at several test potentials. Neither the IBa threshold nor the membrane potentials for the IBa maximum peak amplitude was affected by the temperature change. The concentration-response curves of flavoxate at both 30°C (Ki = 5.1 μM) and 37°C (Ki = 4.6 μM) were slightly shifted to the left in comparison with that at 22°C (Ki = 10.3 μM). Similar results were also obtained in the presence of nifedipine (Ki = 14 nM at 22°C vs. Ki = 2.5 nM at 30°C and Ki = 2.1 nM at 37°C). Altering the bath-solution temperature from 22°C to 30°C shifted the steady-state inactivation curve of IBa at −90 mV to the left. At 30°C, the steady-state inactivation curve of IBa in the presence of flavoxate was also shifted to the left in comparison with that in the absence of flavoxate. Either 3-isobutyl-1-methylxanthine (IBMX) or theophylline, a phosphodiesterase inhibitor, caused little effects on IBa, although cyclic nucleotides (dibutyryl cAMP and 8-Br-cGMP) inhibited IBa. These results suggest that the inhibitory actions of flavoxate on IBa in human detrusor myocytes were slightly changed at different experimental temperatures and that flavoxate directly blocked voltage-dependent L-type Ca2+ channels, not through the inhibition of phosphodiesterase activity pathway.
猫心室肌细胞收缩的激活：低 Cd(2) 浓度和温度的影响。
DOI：
10.1152/ajpheart.1999.277.2.h488
发表时间：
1999
期刊：
The American journal of physiology
影响因子：
--
作者：
Wasserstrom,JA;Vites,AM
通讯作者：
Vites,AM