cAMP-activated chloride conductance in the colonic cell line, Caco-2.
cAMP-activated chloride conductance in the colonic cell line, Caco-2.
复制标题
结肠细胞系 Caco-2 中 cAMP 激活的氯离子电导。
DOI：
10.1152/ajpcell.1992.262.1.c251
复制
发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Reyes,EF
中科院分区：
文献类型：
--
作者：
Bear,CE;Reyes,EF
在这项研究中，我们研究了腺苷3 '，5'-环磷酸（cAMP）刺激的Caco-2细胞单层的Cl-流出的特性，通过测量125 I从预载细胞的流出率和使用膜片钳电生理学。添加含有100 μ M二丁酰cAMP（DBcAMP）、10 μ M毛喉素和1 mM 3-异丁基-1-甲基黄嘌呤的混合物导致125 I流出率显著增加（P <0.05）。通过加入缬氨霉素（4.5 μ M）与135 mM细胞外KCl的细胞电位消散减少cAMP诱发的125 I流出。这些结果表明，cAMP刺激的阴离子流出发生通过导电孔或通道。DBcAMP和forskolin诱发的全细胞电流具有阴离子选择性，PCl大于PI大于Pglucose，并呈线性电流-电压（I-V）关系。去极化或超极化电压阶跃诱发的电流没有显示出时间依赖性激活或失活的证据。单氯离子通道刺激后，与cAMP处理的细胞贴附补丁。cAMP处理20- 30秒后通道活动开始，反应持续时间长。使用两个线性回归，cAMP在细胞贴附贴片中激活的通道的I-V关系最佳拟合。在超极化和去极化电位下，通道的斜率电导分别为3.2 +/- 0.6和7.4 +/- 0.3 pS。在贴片移液管中用70 mM NaCl取代140 mM NaCl导致反转电位的正移，表明通道具有阴离子选择性。（250字处删节）
In this study we investigated the properties of adenosine 3',5'-cyclic monophosphate (cAMP)-stimulated Cl- efflux in Caco-2 monolayers by measuring 125I efflux rates from preloaded cells and using patch-clamp electrophysiology. The addition of a cocktail containing 100 microM dibutyryl cAMP (DBcAMP), 10 microM forskolin, and 1 mM 3-isobutyl-1-methylxanthine caused a significant (P less than 0.05) increase in the rate of 125I efflux. Dissipation of cell potential by adding valinomycin (4.5 microM) with 135 mM extracellular KCl reduced the cAMP-evoked 125I efflux. These results suggest that cAMP-stimulated anion efflux occurs through a conductive pore or channel. Whole cell currents evoked with DBcAMP or forskolin were anion selective, PCl greater than PI greater than Pgluconate, and exhibited a linear current-voltage (I-V) relationship. Currents evoked with depolarizing or hyperpolarizing voltage steps showed no evidence of time-dependent activation or inactivation. Single Cl- channels were stimulated in cell-attached patches after treatment with cAMP. Onset of channel activity occurred after 20-30s of cAMP treatment, and the response was long lasting. The I-V relationship for the channel activated in cell-attached patches by cAMP was best fit using two linear regressions. The slope conductance of the channel was 3.2 +/- 0.6 and 7.4 +/- 0.3 pS at hyperpolarizing and depolarizing potentials, respectively. Substitution of 140 mM NaCl with 70 mM NaCl in the patch pipette resulted in a positive shift in reversal potential, indicating that the channel is anion selective.(ABSTRACT TRUNCATED AT 250 WORDS)
登录
查看更多内容
影响因子：
64.8
作者：
J. Tabcharani;X. Chang;J. Riordan;J. Hanrahan
通讯作者：
J. Tabcharani;X. Chang;J. Riordan;J. Hanrahan
影响因子：
56.9
作者：
ANDERSON, MP;RICH, DP;WELSH, MJ
通讯作者：
WELSH, MJ
DOI：
10.1073/pnas.87.13.4956
发表时间：
1990-07-01
影响因子：
11.1
作者：
CLIFF, WH;FRIZZELL, RA
通讯作者：
FRIZZELL, RA
上皮细胞系 T84 中 cAMP 激活低电导氯离子通道
影响因子：
3.5
作者：
J. Tabcharani;W. Low;D. Elie;J. Hanrahan
通讯作者：
J. Hanrahan