Beck F X, Dörge A, Giebisch G, Thurau K
Department of Physiology, University of Munich, Federal Republic of Germany.
Kidney Int. 1988 Oct;34(4):455-62. doi: 10.1038/ki.1988.202.
A combination of clearance and electron microprobe studies was carried out to investigate renal rubidium excretion and rubidium distribution between plasma and individual tubule cells. Saline-infused animals were compared with potassium-loaded rats and another group in which rubidium was given in such amounts that the sum of plasma rubidium plus potassium equalled the potassium concentration in the potassium-loaded rats. The renal clearance of rubidium was uniformly less than that of potassium. Nevertheless, rubidium stimulated fractional potassium excretion above the levels observed in both saline- and potassium-loaded animals. When compared with their plasma concentrations, rubidium was concentrated in all tubule cell types more than potassium, and this is most likely due to restriction of passive diffusion of rubidium from cells to extracellular fluid. In addition, heterogeneity of intercalated cell ion composition was observed: one cell group had high chloride and potassium, but low rubidium contents, whereas the other was characterized by low chloride and potassium, but high rubidium contents.
进行了清除率和电子微探针研究相结合的实验，以探究肾脏铷排泄以及铷在血浆与单个肾小管细胞之间的分布情况。将输注生理盐水的动物与补钾大鼠以及另一组动物进行比较，在另一组动物中给予铷的量使得血浆铷与钾的总和等于补钾大鼠的钾浓度。铷的肾脏清除率始终低于钾的清除率。然而，铷刺激了钾排泄分数高于在输注生理盐水和补钾动物中观察到的水平。与它们的血浆浓度相比，铷在所有肾小管细胞类型中的浓缩程度都高于钾，这很可能是由于铷从细胞向细胞外液的被动扩散受到限制。此外，观察到闰细胞离子组成的异质性：一组细胞具有高氯和高钾，但铷含量低，而另一组细胞的特征是低氯和低钾，但铷含量高。
