title: Regulation of intracellular chloride concentration in rat lactotrope cells and its relation to the membrane resting potential.
abstract: Rat lactotrope cells in primary culture exhibit physiological properties closely associated with chloride ions (Cl-) homeostasis. In this work, we studied the regulation of intracellular Cl- concentrations ([Cl-]i) and its relation to the membrane resting potential, using a combination of electrophysiology and spectrofluorimetry. Variations in [Cl-]i resulting from the patch clamp technique, pHi, antagonists of Cl(-)-Ca(2+)-dependent channels, an anion exchanger antagonist, and an antagonist of K(+)-Cl- cotransport were considered with respect to their involvement in membrane potential. We show that: (i) The patch-pipette does not always impose its Cl- concentration. (ii) In rat lactotrope cells, membrane resting potential is partially determined by [Cl-]i. (iii) Besides ion channel activity, electroneutral ion transports (cotransports such as K(+)-Cl- and Na(+)-K(+)-2Cl-) participate actively in maintaining a high [Cl-]i. (iv) Finally, Cl- homeostasis is probably linked to cell energetics.
authors.affiliation: CNRS UMR 5543, Université Victor Segalen Bordeaux 2, Bordeaux, France.
authors.forename: P
authors.initials: P
authors.lastname: Sartor
authors.forename: L
authors.initials: L
authors.lastname: Garcia
authors.forename: F
authors.initials: F
authors.lastname: Madec
authors.forename: L
authors.initials: L
authors.lastname: Dufy-Barbe
authors.forename: M
authors.initials: M
authors.lastname: Rigoulet
authors.forename: B
authors.initials: B
authors.lastname: Dufy
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000502:physiology*; D002478:Cells, Cultured; D002713:Chlorine / Q000378:metabolism*; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D007424:Intracellular Fluid / Q000378:metabolism; D008564:Membrane Potentials / Q000502:physiology*; D010903:Pituitary Gland, Anterior / Q000502:physiology*; D011388:Prolactin / Q000096:biosynthesis; D051381:Rats
chemical_list: D002713:Chlorine; D011388:Prolactin