Effect of barium on cell volume regulation in rabbit proximal straight tubules.
Effect of barium on cell volume regulation in rabbit proximal straight tubules.
复制标题
钡对兔近端直管细胞体积调节的影响。
DOI：
10.1152/ajprenal.1985.249.1.f20
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Sullivan,LP
中科院分区：
文献类型：
--
作者：
Welling,PA;Linshaw,MA;Sullivan,LP
当暴露于低渗介质时，家兔近端直小管突然肿胀，但在溶质和水分丢失后，随着接近其基线体积，在几分钟内收缩。在此过程中，主要的细胞内阳离子钾和钠都会丢失。在本实验中，我们研究了低渗细胞的容量调节存在的钡，一个代理报告，以减少钾的渗透性。暴露于氯化钡显着延长低渗容量恢复的剂量依赖性方式。通过暴露于10（-4）M哇巴因1 h，使钾耗尽并装载氯化钠的小管发生渗透压膨胀，随后在稀释培养基中调节体积。这种小管的体积调节是跨基底膜流体静力的结果。相比之下，肾小管同样负载钠，但也暴露于10（-3）M BaCl 2，在稀释培养基中体积调节仅为最低限度，表明BaCl 2也可能影响钠的运动。然而，低渗容量调节恢复在钠加载氯化钡处理的小管时，细胞更有效地耗尽钾孵育在0 mM钾培养基。我们的结论是，钡延迟低渗容量调节主要是因为它对钾运动的影响。
Rabbit proximal straight tubules swell abruptly when exposed to hypotonic medium but then shrink in a few minutes as they approach their base-line volume following loss of solute and water. Potassium, the major intracellular cation, as well as sodium, is lost during this process. In the present experiments, we studied hypotonic cell volume regulation in the presence of barium, an agent reported to decrease potassium permeability. Exposure to BaCl2 significantly prolonged hypotonic volume recovery in a dose-dependent manner. Tubules depleted of potassium and loaded with sodium chloride by exposure to 10(-4) M ouabain for 1 h swelled osmometrically and subsequently volume regulated in dilute medium. Volume regulation in such tubules is a consequence of transbasement membrane hydrostatic forces. By contrast, tubules similarly loaded with sodium, but also exposed to 10(-3) M BaCl2, volume regulated only minimally in dilute medium, suggesting BaCl2 might also affect sodium movement. However, hypotonic volume regulation was restored in sodium-loaded BaCl2-treated tubules when cells were more effectively depleted of potassium by incubation in 0-mM potassium medium. We conclude that barium retards hypotonic volume regulation primarily because of its effect on potassium movement.