Potassium in the rat kidney proximal tubules in situ: Determination by K+-selective liquid ion-exchange microelectrodes
- 29 Downloads
Intraluminal K+ concentration in the rat kidney proximal tubule was measured in situ by means of K+-selective liquid ion-exchange microelectrodes. By virtue of its independence of sampling techniques, the in situ measurement is more accurate in dealing with fluids flowing through microtubular structures. Using K+-selective liquid ion-exchange microelectrodes it was observed that the K+ concentration falls along the length of the proximal convoluted tubule. The mean (TF/P) K concentration ratio of 0.89±0.01 for the first convolution is significantly greater (p<0.001) than the mean ratio of 0.81±0.01 for the last convolution of the proximal tubule. A description is given of the construction and calibration of the K+-selective microelectrode with a new liquid ion-exchanger.
Key-WordsPotassium Microelectrode Liquid Ion-Exchange Microelectrode Proximal Tubule Potassium
SchlüsselwörterKalium-Mikroelektrode Flüssigkeits-Ionenaustausch-Mikroelektrode Kalium in proximalen Tubuli
Unable to display preview. Download preview PDF.
- 1.Bloomer, H. A., Rector, F. C., Jr., Seldin, D. W.: The mechanism of potassium reabsorption in the proximal tubule of the rat. J. clin. Invest.42, 277 (1963).Google Scholar
- 2.Khuri, R. N., Flanigan, W. J., Oken, D. E.: Potassium in proximal tubule fluid of rats and necturus measured with glass electrodes. J. appl. Physiol.21, 1568 (1966).Google Scholar
- 3.—, Goldstein, D. A., Maude, D. L., Edmonds, C., Solomon, A. K.: Single proximal tubules of the necturus kidney: Na and K determination by glass electrodes. Amer. J. Physiol.204, 743 (1963).Google Scholar
- 4.Litchfield, J. B., Bott, P. A.: Micropuncture study of renal excretion of water, K, Na, and Cl in the rat. Amer. J. Physiol.203, 667 (1962).Google Scholar
- 5.Malnic, G., Klose, R. M., Giebisch, G.: Micropuncture study of renal potassium excretion in the rat. Amer. J. Physiol.206, 674 (1964).Google Scholar
- 6.Marsh, D. G., Ullrich, K. J., Rumrich, G.: Micropuncture analysis of the behavior of potassium ions in rat renal cortical tubules. Arch. ges. Physiol.277, 107, (1963).Google Scholar
- 7.Settzo, R. J., Wise, W. M.: Liquid organic ion-exchanger electrode with organophilic-hydrophobic membrane. U.S. Patent No. 3,448,032 (1969).Google Scholar
- 8.Wise, W. M., Kurey, M. J., Baum, G.: Direct potentiometric measurement of potassium in blood serum with liquid ion-exchange electrode. Clin. Chem.16, 103 (1970).Google Scholar