Purinergic and cholinergic agonists induce exocytosis from the same granule pool in HT29-Cl.16E monolayers
Purinergic and cholinergic agonists induce exocytosis from the same granule pool in HT29-Cl.16E monolayers
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DOI：
10.1152/ajpcell.1999.276.4.c907
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发表时间：
1999-04-01
影响因子：
5.5
通讯作者：
Hopfer, U
中科院分区：
文献类型：
--
作者：
Bertrand, CA;Laboisse, CL;Hopfer, U
几种促分泌剂通过测量释放的颗粒含量来诱导上皮单分子层粘蛋白的分泌。为了评估不同的激动剂是否作用于同一颗粒池，用一种新的阻抗方法测量了杯状细胞系HT29-C1.16E完整单层的电容变化。顶端ATP(嘌呤能激动剂)和基底外侧卡巴胆碱(胆碱能激动剂)引起快速胞吐，最大电容变化在3min内。最佳浓度的激动剂诱导的最大胞吐水平是相同的，并产生30-40%的总单层电容增加。当同时应用三磷酸腺苷和卡巴胆碱时，胞吐作用的大小与单一促分泌剂的水平没有变化。ATP刺激后电容恢复到基线(内吞作用)的速度明显快于氨基甲胆碱刺激后。当ATP和卡巴胆碱以产生最大胞吐作用的剂量顺序应用时，第二促分泌剂产生的电容增加的幅度小于或等于恢复期内电容减少的幅度。总而言之，这些数据表明，嘌呤能和胆碱能激动剂作用于同一颗粒池。
Several secretagogues induce mucin secretion in epithelial monolayers, as determined by measuring released granule contents. To assess whether different agonists act on the same granule pool, capacitance changes in intact monolayers of the goblet cell line HT29-C1.16E were measured by a novel impedance method. Apical ATP (purinergic agonist) and basolateral carbachol (cholinergic agonist) induce rapid exocytosis with maximal capacitance changes within 3 min. The maximal levels of exocytosis that can be induced by optimal concentrations of either agonist are the same and produce a 30-40% increase in total monolayer capacitance. When ATP and carbachol are applied simultaneously, the magnitude of exocytosis is unchanged from the single-secretagogue level. The recovery of capacitance to baseline (endocytosis) is significantly faster after ATP stimulation than after carbachol stimulation. When ATP and carbachol are applied sequentially at doses that give maximal exocytosis, the magnitude of the capacitance increase produced by the second secretagogue is less than or equal to that of the capacitance decrease during the recovery period. Together, these data suggest that purinergic and cholinergic agonists act on the same granule pool.