Transmembrane chloride flux in tissue-cultured chick heart cells

Journal Article · Sun May 01 04:00:00 EDT 1983 · J. Gen. Physiol.; (United States)

DOI:https://doi.org/10.1085/jgp.81.5.731· OSTI ID:6743163

Piwnica-Worms, D; Jacob, R; Horres, C R; Lieberman, M

To evaluate the transmembrane movement of chloride in a preparation of cardiac muscle lacking the extracellular diffusion limitations of natural specimens, intracellular chloride concentration ( (Cl) i) and transmembrane /sup 36/Cl efflux have been determined in growth-oriented embryonic chick heart cells in tissue culture. Using the method of isotopic equilibrium, (Cl)i was 25.1 +/- 7.3 mmol x (liter cell water)-1, comparable to the value of 24.9 +/- 5.4 mmol x (liter cell water)-1 determined by coulometric titration. Two cellular /sup 36/Cl compartments were found; one exchanged with a rate constant of 0.67 +/- 0.12 min-1 and was associated with the cardiac muscle cells; the other, attributed to the fibroblasts, exchanged with a rate constant of 0.18 +/- 0.05 min-1. At 37 degrees C, transmembrane Cl flux of cardiac muscle under steady-state conditions was 30 pmol x cm-2 x s-1. In K-free, normal, or high-Ko solutions, the responses of the membrane potential to changes in external Cl concentration suggested that chloride conductance was low. These results indicate that Cl transport across the myocardial cell membrane is more rapid than K transport and is largely electrically silent.

• Research Organization: Duke Univ. Medical Center, Durham, NC
• OSTI ID: 6743163
• Journal Information: J. Gen. Physiol.; (United States), Journal Name: J. Gen. Physiol.; (United States) Vol. 81:5; ISSN JGPLA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIRDS
BODY
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
CELL MEMBRANES
CHICKENS
CHLORIDES
CHLORINE 36
CHLORINE COMPOUNDS
CHLORINE ISOTOPES
COMPARTMENTS
ELECTRON CAPTURE RADIOISOTOPES
EMBRYOS
FOWL
HALIDES
HALOGEN COMPOUNDS
HEART
IN VITRO
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MEMBRANE TRANSPORT
MEMBRANES
MUSCLES
NUCLEI
ODD-ODD NUCLEI
ORGANS
RADIOISOTOPES
TRACER TECHNIQUES
VERTEBRATES
YEARS LIVING RADIOISOTOPES