title: Depolarization of cell membrane is associated with an increase in ciliary beat frequency (CBF).
abstract: We hypothesize that activation of muscarinic cholinergic receptors depolarizes the cell membrane of the mammalian ciliated cells which in turn causes an increase of CBF. To test this hypothesis, a di-8-ANEPPS fluorescence photon counting and nonstationary heterodyne laser light scattering system was developed to measure cell membrane potential (psi) and CBF in cultured ovine tracheal ciliated cells simultaneously. Carbachol dose dependently depolarized the cell membrane with a corresponding stimulation of CBF. The carbachol induced depolarization of cell membrane and increases of CBF were inhibited by prior application of either atropine or verapamil or amiloride. These novel data suggest that depolarization of the cell membrane and the corresponding stimulation of CBF caused by the activation of muscarinic receptors of the mammalian ciliated cells are dependent on the influx of either extracellular Ca2+ or Na+.
mesh_terms: D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D002923:Cilia / Q000187:drug effects / Q000502:physiology*; D005456:Fluorescent Dyes; D015759:Ionomycin / Q000494:pharmacology; D007700:Kinetics; D008856:Microscopy, Fluorescence / Q000295:instrumentation / Q000379:methods; D018721:Muscarinic Agonists / Q000494:pharmacology*; D017785:Photons; D011726:Pyridinium Compounds; D011976:Receptors, Muscarinic / Q000502:physiology*; D012542:Scattering, Radiation; D012756:Sheep; D013997:Time Factors; D014132:Trachea / Q000187:drug effects / Q000502:physiology*; D014700:Verapamil / Q000494:pharmacology
chemical_list: C089669:1-(3-sulfonatopropyl)-4-(beta-(2-(di-n-octylamino)-6-naphthyl)vinyl)pyridinium betaine; D005456:Fluorescent Dyes; D018721:Muscarinic Agonists; D011726:Pyridinium Compounds; D011976:Receptors, Muscarinic; D015759:Ionomycin; D001285:Atropine; D000584:Amiloride; D002217:Carbachol; D014700:Verapamil