Beck F X, Dörge A, Blümner E, Giebisch G, Thurau K
Department of Physiology, University of Munich, Federal Republic of Germany.
Kidney Int. 1988 Mar;33(3):642-51. doi: 10.1038/ki.1988.47.
Rubidium uptake into individual tubule cells of rat renal cortex as measured by energy-dispersive X-ray microanalysis on freeze dried cryosections was used as an index of potassium transport. Over a 30 second period following intravenous infusion of rubidium (0.5 mmol/kg body wt) rubidium content increased in all cells. After 30 seconds, rubidium contents were (in mmol/kg dry wt): 225 +/- 8 in distal convoluted tubule cells, 156 +/- 7 in connecting tubule cells, 110 +/- 7 in principal cells, 86 +/- 4 in proximal tubule cells and 24 +/- 2 in intercalated cells (mean +/- SEM). When distal sodium and potassium transport were stimulated by hypertonic saline loading, rubidium uptake was selectively increased into distal convoluted tubule cells by 38%, into connecting tubule cells by 36%, and into principal cells by 52%. However, rubidium uptake into proximal tubule and into intercalated cells remained unchanged. The preferential uptake of rubidium into distal convoluted tubule cells, connecting tubule cells, and principal cells correlates well with the known transport functions of sodium and potassium, whereas intercalated cells are distinguished by low sodium and potassium transport activity.
通过对冷冻干燥的冰冻切片进行能量色散X射线微分析来测量铷进入大鼠肾皮质单个肾小管细胞的情况，以此作为钾转运的指标。在静脉注射铷（0.5 mmol/kg体重）后的30秒内，所有细胞中的铷含量均增加。30秒后，铷含量（以mmol/kg干重计）分别为：远曲小管细胞225±8，连接小管细胞156±7，主细胞110±7，近端小管细胞86±4，闰细胞24±2（均值±标准误）。当通过高渗盐水负荷刺激远曲小管的钠和钾转运时，铷进入远曲小管细胞的摄取量选择性增加38%，进入连接小管细胞的摄取量增加36%，进入主细胞的摄取量增加52%。然而，铷进入近端小管细胞和闰细胞的摄取量保持不变。铷优先摄取进入远曲小管细胞、连接小管细胞和主细胞，这与已知的钠和钾转运功能密切相关，而闰细胞的特点是钠和钾转运活性较低。
