title: Cellular mechanisms in activation of Na-K-Cl cotransport in nasal gland acinar cells of guinea pigs.
abstract: The cellular regulation mechanism of Na-K-Cl cotransport was studied in dispersed acinar cells of the guinea pig nasal gland by a microfluorimetric imaging method using the Na(+)-sensitive dye sodium-binding benzofuran isophthalate. Addition of 1 micron acetylcholine (ACh) induced an immediate increase in intracellular Na+ concentration ([Na+]i) by 36.7 +/- 9.9 mM, which was almost completely abolished by the addition of atropine. The increased [Na+]i after cholinergic stimulation was due to the external (Cl-)-dependent cotransport system (about 80% of the total Na+ influx) and the dimethyl amiloride-sensitive (Na+)-H+ exchange system (of about 20%). The ACh-induced increase in [Na+]i was dependent on extracellular Ca2+ and was prevented by pretreatment with 8-(N, N-diethylamino)octyl-3,4,5-trimethoxybenzoate or O-O'-bis(2-aminophenyl)ethyleneglycol-N, N, N', N'-tetraacetic acid tetraacetoxymethylester. Addition of 1 microns ionomycin mimicked the ACh-induced increase in [Na+]i which was dependent on external Cl-. Moreover, both a calmodulin antagonist trifluoperazine and a myosin light chain kinase inhibitor ML-7 reduced the ACh-induced response in [Na+]i. However, the following treatment did not affect the basal [Na+]i nor the ACh-induced increase in [Na+]i: (i) addition of dibutyryl cAMP, 8-Br-cGMP, or phorbol 12-myristate 13-acetate, (ii) pretreatment of protein kinase inhibitors, H-89, H-8, H-7 or chelerythrine, (iii) prevention of cytosolic Cl- efflux by the addition of diphenylamine-2-carboxylic acid or, (iv) prevention of cytosolic K+ efflux by the addition of charybdotoxin.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Otolaryngology, Tohoku University School of Medicine Sendai, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ikeda
authors.forename: D
authors.initials: D
authors.lastname: Wu
authors.forename: T
authors.initials: T
authors.lastname: Takasaka
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000470:Alkaloids; D000818:Animals; D053119:Benzophenanthridines; D001692:Biological Transport / Q000187:drug effects; D003994:Bucladesine / Q000494:pharmacology; D002034:Bumetanide / Q000494:pharmacology; D002118:Calcium / Q000502:physiology; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000502:physiology; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018999:Charybdotoxin / Q000494:pharmacology; D002799:Cholinergic Fibers / Q000502:physiology*; D000242:Cyclic AMP / Q000494:pharmacology / Q000502:physiology; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005088:Exocrine Glands / Q000187:drug effects / Q000294:innervation / Q000378:metabolism*; D005665:Furosemide / Q000494:pharmacology; D006168:Guinea Pigs; D015759:Ionomycin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology; D009296:Nasal Cavity; D010617:Phenanthridines / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000502:physiology; D015290:Second Messenger Systems; D015398:Signal Transduction / Q000187:drug effects*; D012964:Sodium / Q000378:metabolism*; D028021:Sodium-Potassium-Chloride Symporters; D013449:Sulfonamides; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014268:Trifluoperazine / Q000494:pharmacology; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology
chemical_list: D000470:Alkaloids; D053119:Benzophenanthridines; D002147:Calmodulin; D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D007476:Ionophores; D007546:Isoquinolines; D010617:Phenanthridines; D047428:Protein Kinase Inhibitors; D028021:Sodium-Potassium-Chloride Symporters; D013449:Sulfonamides; D002034:Bumetanide; D018999:Charybdotoxin; D014268:Trifluoperazine; C016276:8-bromocyclic GMP; D014660:Vasoactive Intestinal Peptide; D015759:Ionomycin; D003994:Bucladesine; D005665:Furosemide; D012964:Sodium; D000242:Cyclic AMP; C016299:chelerythrine; D011494:Protein Kinases; D006152:Cyclic GMP; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide; D000109:Acetylcholine; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium