Intracellular Chloride Activity and the Effect of 5-Hydroxytryptamine on the Chloride Conductance of Leech Retzius Neurons

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.

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Intracellular chloride activity of frog sartorius muscle

The Japanese Journal of Pharmacology ◽

10.1016/s0021-5198(19)66322-5 ◽

1979 ◽

Vol 29 ◽

pp. 138

Author(s):

Shoji Morimoto ◽

Yoshio Ikari ◽

Testuji Hironaka

Keyword(s):

Sartorius Muscle ◽

Intracellular Chloride ◽

Frog Sartorius Muscle ◽

Frog Sartorius ◽

Intracellular Chloride Activity ◽

Chloride Activity

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

The Journal of General Physiology ◽

10.1085/jgp.70.4.507 ◽

1977 ◽

Vol 70 (4) ◽

pp. 507-530 ◽

Cited By ~ 33

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.

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