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.
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Khuri, R.N., Agulian, S.K. & Wise, W.M. Potassium in the rat kidney proximal tubules in situ: Determination by K+-selective liquid ion-exchange microelectrodes. Pflugers Arch. 322, 39–46 (1971). https://doi.org/10.1007/BF00586663
- Potassium Microelectrode
- Liquid Ion-Exchange Microelectrode
- Proximal Tubule Potassium
- Kalium in proximalen Tubuli