Recording of a large-conductance chloride channel in normal rat lactotrophs.
Membrane current fluctuations resembling channel openings and closings were observed in the whole cell configuration of the patch-clamp technique in normal rat lactotrophs in primary culture. Using high-gain head stage in whole cell configuration, we characterized the nature and pharmacological properties of the ionic channel underlying these fluctuations. This channel, found in small numbers (< 10 per cell), was specific for Cl- because its reversal potential varied with Cl- gradients, according to the Nernst equation, and its unitary amplitude was linearly related to membrane potential from -100 to 0 mV. Slope conductance was close to 100 pS. Analyzing open times, we demonstrated its Ca2+ and potential dependence. Four sublevels were observed. We suggest that this channel, belonging to the background Cl- channel group, takes part in the regulation of intracellular Cl- concentration of normal rat lactotrophs.
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000494:pharmacology; D000818:Animals; D018118:Chloride Channels / Q000037:antagonists & inhibitors / Q000502:physiology*; D004553:Electric Conductivity; D005260:Female; D013006:Growth Hormone / Q000378:metabolism; D007150:Immunohistochemistry; D018408:Patch-Clamp Techniques; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D012016:Reference Values
D018118:Chloride Channels; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D011388:Prolactin; D013006:Growth Hormone; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid