cis-FFA do not alter membrane depolarization but block Ca2+ influx and GH secretion in KCl-stimulated somatotroph cells. Suggestion for a direct cis-FFA perturbation of the Ca2+ channel opening.
It has been reported that cis-unsaturated free fatty acids (cis-FFA) block intracellular Ca2+ rise in EGFR T17 and GH3 cells by perturbing the generation of Ins(1,4,5)P3. In the present work, it was found that cis-FFA did not alter potassium-induced cell depolarization in GH3 cells, while blocking Ca2+ rise and GH secretion. Interestingly enough, saturated or trans-unsaturated FFA exert the opposite actions, i.e., they block cell depolarization without altering Ca2+ rise and hormone secretion. As depolarization activates GH3 cells via direct opening of Ca2+ channels with no generation of intracellular mediators, these results suggest that cis-FFA act by a direct perturbation of the Ca2+ channel opening.
Pérez
F R
FR
Department of Medicine, Compostela University School of Medicine and Complejo Hospitalario Universitario de Santiago, Santiago de Compostela, Spain.
Camiña
J P
JP
Zugaza
J L
JL
Lage
M
M
Casabiell
X
X
Casanueva
F F
FF
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000737:chemistry / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D000431:Ethanol / Q000494:pharmacology; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology*; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D006096:Gramicidin / Q000494:pharmacology; D013006:Growth Hormone / Q000378:metabolism*; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D009553:Nimodipine / Q000494:pharmacology; D019301:Oleic Acid / Q000494:pharmacology; D009829:Oleic Acids; D010902:Pituitary Gland / Q000187:drug effects / Q000502:physiology*; D010911:Pituitary Neoplasms; D011189:Potassium Chloride / Q000494:pharmacology*; D011388:Prolactin / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013229:Stearic Acids / Q000494:pharmacology; D013237:Stereoisomerism; D014407:Tumor Cells, Cultured
D015220:Calcium Channels; D005230:Fatty Acids, Nonesterified; D005231:Fatty Acids, Unsaturated; D009829:Oleic Acids; D013229:Stearic Acids; D006096:Gramicidin; D019301:Oleic Acid; D000431:Ethanol; C011459:elaidic acid; C031183:stearic acid; D009553:Nimodipine; D011189:Potassium Chloride; D011388:Prolactin; D013006:Growth Hormone; D002118:Calcium