Gilles R, Duchene C, Lambert I
Am J Physiol. 1983 Jun;244(6):F696-705. doi: 10.1152/ajprenal.1983.244.6.F696.
Rabbit kidney cortex slices behave an osmometers when withstanding hyperosmotic or hyposmotic shocks of amplitude up to pi 1/pi 2 = 1.25. For hyposmotic shocks of amplitude larger than or equal to pi 1/pi 2 = 1.50, the maximum swelling achieved is less than what can be expected on the basis of the van't Hoff relation, thereby indicating that a volume regulation process is taking place. Volume regulation in kidney slices can be dissociated into two distinct phases. The first one, of swelling limitation, is very rapid and keeps maximum cell volume at values lower than expected when the tissue is considered as an osmometer. This phase is followed by a slow volume readjustment process during which volume progressively decreases towards control values. The major intracellular osmotic effector loss during both swelling limitation and volume readjustment is Na+. The overall volume regulation process is insensitive to furosemide, vanadate, and bumetanide. Swelling limitation is blocked by addition of ouabain. Contrary to what has been believed previously, there is, however, no need to implicate control of the activity of a ouabain-sensitive, Na+/K+ pump in the Na-dependent volume regulation mechanism.
当承受幅度高达π1/π2 = 1.25的高渗或低渗冲击时，兔肾皮质切片表现出渗透压计的特性。对于幅度大于或等于π1/π2 = 1.50的低渗冲击，所达到的最大肿胀小于根据范特霍夫关系预期的值，从而表明正在发生体积调节过程。肾切片中的体积调节可分为两个不同阶段。第一个阶段是肿胀限制，非常迅速，使最大细胞体积保持在低于将组织视为渗透压计时预期的值。此阶段之后是一个缓慢的体积重新调整过程，在此过程中体积逐渐向对照值下降。在肿胀限制和体积重新调整过程中，主要的细胞内渗透效应物损失是Na+。总体体积调节过程对速尿、钒酸盐和布美他尼不敏感。加入哇巴因可阻断肿胀限制。然而，与先前的看法相反，在钠依赖性体积调节机制中，无需涉及对哇巴因敏感的Na+/K+泵活性的控制。
