Abstract
A simple device for fluid exchange is described, which allows the exchange of an unlimited number of solutions at low (10–1000 nl/min) constant perfusion rate. The applicability of the system has been tested in microperfusion experiments of rat distal tubules. At a luminal perfusion rate of 40 nl/min, the lag time was some 20 sec and 80 % fluid exchange time some 3 sec. Simple modification allows further reduction of the lag time. Under control conditions, the potential difference across the late distal tubule (PDte) approaches −19.4±2.5 mV (n = 27). Increase of luminal potassium concentration from 5.4 to 40 mmol/l hyperpolanzes PDte to −29.9±4.3 mV (n = 8). Amiloride (10 μmol/l) leads to a reversible depolarization to −3.2±1.0 mV (n = 19), barium (1 mmol/l) to a reversible hyperpolarization to −25.8±2.6 mV (n = 19). As expected, PDte is largely created by amiloride sensitive sodium channels and is partially blunted by barium sensitive potassium channels.
References
Barratt LJ (1976) The effect of amiloride on the transepithelial potential difference of the distal tubule of the rat kidney. Pflügers Arch 361: 251–254
Deetjen P, Silbernagl S (1972) Some new developments in continuous microperfusion technique. Yale J Biol Med 45: 301–306
Ellison DH, Velazquez H, Wright FS (1985) Stimulation of distal potassium secretion by low lumen chloride in the presence of barium. Am J Physiol 248: F638-F649
Frömter E (1982) Electrophysiological analysis of rat renal sugar and amino acid transport. I. Basic phenomena. Pflügers Arch 393: 179–189
Gross P, Minuth WW, Kriz W, Frömter E (1986) Electrical properties of renal collecting duct principal cell epithelium in tissue culture. Pflügers Arch 406: 380–386
Gross P, Minuth WW, Ketteler M, Frömter E (1988) Ionic conductances of cultured principal cell epithelium of renal collecting duct. Pflügers Arch 412: 434–441
Hierholzer K, Butz M, Müller-Suur R, Lichtenstein I (1972) Pressure measurements in proximal surface tubules of the rat-single nephron filtration rate and tubuloglomerular feedback. Yale J Biol Med 45: 224–232
Lang F, Greger R, Lechene C, Knox FG (1978) Micropuncture techniques. In: Methods in pharmacology (Martinez-Maldonado M, ed), Vol 4B, pp 75–103 (Plenum Pub Corp, New York)
Sonnenberg H, Deetjen P (1964) Methode zur Durchströmung einzelner Nephronabschnitte. Pflügers Arch 278: 669–674
Steinhausen M (1963) Eine Methode zur Differenzierung proximaler und distaler Tubuli der Nierenrinde von Ratten in vivo und ihre Anwendung zur Bestimmung tubulärer Strömungsgeschwindigkeiten. Pflügers Arch 277: 23–35
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Ritter, M., Lang, F. A simple method for multiple fluid exchange. Pflügers Arch 415, 241–243 (1989). https://doi.org/10.1007/BF00370599
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DOI: https://doi.org/10.1007/BF00370599