Cell swelling increases intracellular free [Ca] in cultured toad bladder cells.
Cell swelling increases intracellular free [Ca] in cultured toad bladder cells.
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培养的蟾蜍膀胱细胞中细胞肿胀增加了细胞内游离 [Ca]。
DOI：
10.1152/ajprenal.1990.258.2.f292
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
ChaseJr,HS
中科院分区：
文献类型：
--
作者：
Wong,SM;DeBell,MC;ChaseJr,HS
我们研究了细胞肿胀对细胞内游离钙浓度（[Ca]i）在培养的蟾蜍膀胱细胞（TB-M）生长作为一个极化单层胶原涂层过滤器的影响。[Ca]i通过使用Fura-2、荧光显微镜和简单的视频成像来测量。在初步实验中，我们确定，降低15%的离子强度对fura-2的Kd没有影响，表明该染料可用于检查细胞溶胀对[Ca]i的影响。将Serbine沐浴培养基的渗透压降低15%导致[Ca]i在10 s内从97 +/- 9增加至354 +/- 88 nM（n = 5）。到2分钟时，[Ca]i下降至163 +/- 22 nM。[Ca]i的增加不是由Na浓度（[Na]）的下降引起的，因为Serbine [Na]的等渗还原并不导致[Ca]i的增加。通过将血清钙浓度降低至200 nM并加入镧，可消除肿胀诱导的[Ca]i增加。钙通道阻滞剂尼群地平和维拉帕米也抑制肿胀诱导的[Ca]i增加，但程度不同。这些实验表明，培养的蟾蜍膀胱细胞的肿胀的结果在[Ca]i的显着增加，通过提高跨基底外侧膜的钙进入的速率，可能通过钙通道。
We examined the effect of cell swelling on intracellular free calcium concentration ([Ca]i) in cultured toad bladder cells (TB-M) grown as a polarized monolayer on collagen-coated filters. [Ca]i was measured by use of fura-2, fluorescence microscopy, and simple video imaging. In preliminary experiments we determined that reducing ionic strength by 15% had no effect on the Kd of fura-2, indicating that the dye could be used to examine the effects of cell swelling on [Ca]i. Reducing the osmolality of the serosal bathing medium by 15% caused [Ca]i to increase within 10 s from 97 +/- 9 to 354 +/- 88 nM (n = 5). By 2 min [Ca]i had declined to 163 +/- 22 nM. The increase in [Ca]i was not caused by a fall in Na concentration ([Na]) because isosmotic reduction of serosal [Na] did not result in an increase in [Ca]i. The swelling-induced increase in [Ca]i could be abolished by lowering serosal [Ca] to 200 nM and by addition of lanthanum. The calcium-channel blockers nitrendipine and verapamil also inhibited the swelling-induced increase in [Ca]i, although to different degrees. These experiments demonstrate that swelling of cultured toad bladder cells results in a significant increase in [Ca]i by enhancing the rate of calcium entry across the basolateral membrane, possibly through a calcium channel.