ISSN:
1432-2013
Keywords:
Distal renal tubule
;
Microperfusion
;
Amiloride
;
Barium
;
Potential difference
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00370599
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