Comparative Studies of Furosemide Effects on Membrane Potential and Intracellular Chloride Activity in Human and Rabbit Ciliary Epithelium

1992 ◽  
Vol 24 (2) ◽  
pp. 83-91 ◽  
Author(s):  
T.C. Chu ◽  
R.R. Socci ◽  
M. Coca-Prados ◽  
Keith Green
Keyword(s):  
Membrane Potential ◽  
Comparative Studies ◽  
Ciliary Epithelium ◽  
Intracellular Chloride ◽  
Intracellular Chloride Activity ◽  
Chloride Activity

Intracellular chloride activity in rabbit papillary muscle: effect of serum

1986 ◽  
Vol 64 (11) ◽  
pp. 1381-1384 ◽  
Author(s):  
Jean-Pierre Caillé
Keyword(s):  
Membrane Potential ◽  
Cardiac Cells ◽  
Equilibrium Potential ◽  
Papillary Muscles ◽  
Experimental Conditions ◽  
Intracellular Chloride ◽  
Intracellular Chloride Activity ◽  
Chloride Activity ◽  
Diastolic Potential

The intracellular chloride activity (aiCl), measured with Cl-selective microelectrodes on stimulated rabbit papillary muscles (1 Hz) incubated in serum, was 7.2 ± 2.2 mM (48 measurements). Under the same condition, on the quiescent muscle, aiCl was 7.5 ± 2.8 mM (45 measurements). The membrane potential of quiescent papillary muscles and diastolic potential of stimulated papillary muscles were −79.0 ± 0.7 (50 measurements) and −83.5 ± 0.5 mV (50 measurements), respectively. The experimental conditions were chosen to reproduce the in vivo conditions where the Cl equilibrium potential is close to the membrane potential or to the diastolic potential. After correcting for cytoplasmic interference (4 mM) on the aiCl measurements, the Cl equilibrium potential (ECl) was −84 mV. In conclusion, the Cl distribution in cardiac cells bathed in serum is passive as for in vivo cardiac cells.

Intracellular chloride activity in intact rat liver: relationship to membrane potential and bile flow

1987 ◽  
Vol 252 (5) ◽  
pp. G699-G706
Author(s):  
J. G. Fitz ◽  
B. F. Scharschmidt
Keyword(s):  
Membrane Potential ◽  
Bile Flow ◽  
Chloride Transport ◽  
Basolateral Membrane ◽  
Bile Formation ◽  
Intracellular Chloride ◽  
Canalicular Bile ◽  
Intracellular Chloride Activity ◽  
Chloride Activity

Active chloride transport has been described in a variety of epithelia, and intracellular chloride activity (aiCl) in these tissues is generally elevated twofold or more above the level predicted for passive diffusion. To determine whether active chloride transport might contribute to canalicular bile formation, we have used conventional and Cl- -selective microelectrodes to measure aiCl of rat hepatocytes in vivo under a variety of conditions. Under basal conditions, the membrane potential difference averaged -33.2 +/- 3.5 mV (means +/- SD) in 29 animals, and the ratio (R) of observed aiCl (24.8 mM) to that expected for passive distribution at this membrane potential (22.6 mM) was 1.10 +/- 0.08, a value slightly but significantly greater than that predicted for passive distribution. Infusion of alanine (45-mumol bolus, 10.8-mumol/min infusion) in 5 animals hyperpolarized the membrane potential to -43.6 +/- 4.0 mV over 10-15 min and resulted in a significant fall in aiCl to 15.1 +/- 4.8 mM but with no change in R. Infusion of theophylline (577 nmol/min), taurocholate (3-mumol bolus, 810-nmol/min infusion), and ursodeoxycholic acid (4-mumol bolus, 2.13-mumol/min infusion) into 5 animals each increased bile flow by 6.1, 34.1, and 96.8%, respectively, compared with saline-infused controls but did not alter membrane potential or chloride distribution. These observations indicate that aiCl is close to the level predicted for passive distribution under basal conditions, after hyperpolarization of the membrane potential by alanine, and after stimulation of bile flow by a variety of choleretics. By analogy with Cl- -secreting epithelia, it appears unlikely that active chloride transport across the basolateral membrane contributes significantly to canalicular bile formation by the hepatocyte.

scholarly journals Liquid and solid-state Cl- -sensitive microelectrodes. Characteristics and application to intracellular Cl- activity in Balanus photoreceptor.

1977 ◽  
Vol 70 (4) ◽  
pp. 507-530 ◽  
Author(s):  
J H Saunders ◽  
H M Brown
Keyword(s):  
Solid State ◽  
Organic Anion ◽  
Intracellular Chloride ◽  
Glass Microelectrode ◽  
Biological Interest ◽  
Intracellular Chloride Activity ◽  
Chloride Activity

When intracellular chloride activity (aiCl) was monitored with chloride-sensitive liquid ion exchanges (CLIX) microelectrodes in Balanus photoreceptors, replacement of extracellular chloride (Cl0) by methanesulfonate or glutamate was followed by a rapid but incomplete loss of aiCl. When propionate was used as the extracellular anion substitute, CLIX electrodes detected an apparent gain in aiCl, while a newly designed Ag-AgCl wire-in glass microelectrode showed a loss of aiCl under the same conditions. This discrepancy in Cl- washout when propionate replaced Cl0 is explained by the differences in selectivity of CLIX and Ag-AgCl electrodes for native intracellular anions and for the extracellular anion substitute which also replaces Cli and interferes in the determination of aiCl. Both electrodes indicate that ECl approximately Em when the cells are bathed in normal barnacle saline, and both electrodes showed the rate of Cl washout (tau approximately 5 min) to be independent of Cli when Cl0 was replaced by glutamate. Details of Ag-AgCl microelectrode construction are presented. These electrodes were tested and found to be insensitive to the organic anion substitutes used in this study. Selectivity data of CLIX electrodes for several anions of biological interest are described.

Intracellular Chloride Activity of Crayfish Giant Axons

Nature ◽  
1965 ◽  
Vol 208 (5012) ◽  
pp. 790-791 ◽  
Author(s):  
A. STRICKHOLM ◽  
B. G. WALLIN
Keyword(s):  
Giant Axons ◽  
Intracellular Chloride ◽  
Intracellular Chloride Activity ◽  
Chloride Activity
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