Ionic currents evoked by acetylcholine in isolated acinar cells of the guinea pig nasal gland.
The patch-clamp whole cell recording was used to demonstrate activation of membrane conductance to K+, Cl- and cations induced by acetylcholine (ACh) in the isolated acinar cells of the guinea pig nasal gland. A small outward K+ current at 0 mV and a large transient and sustained inward current at -90 mV were evoked by ACh and ACh-evoked reversal potential was about -3 mV nearly to Cl- equilibrium potential in 140 mM KCl in the pipette and physiological saline in the bath. The ionic substitutional experiments indicated that ACh-evoked inward currents were carried by both Cl- and cations. Both outward and inward currents evoked by ACh were almost completely abolished by removal of external Ca2+ and mimicked those evoked by a calcium ionophore A23187. These findings indicate that ACh-evoked membrane conductances are mediated by an increase in intracellular Ca2+.
Department of Otolaryngology, Tohoku University School of Medicine, Sendai, Japan.
D
D
Wu
H
H
Sunose
K
K
Ikeda
M
M
Ishigaki
T
T
Takasaka
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D002712:Chlorides / Q000378:metabolism; D004533:Egtazic Acid / Q000494:pharmacology; D004553:Electric Conductivity / Q000187:drug effects; D005071:Evoked Potentials / Q000187:drug effects; D005088:Exocrine Glands / Q000187:drug effects / Q000502:physiology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009666:Nose; D011188:Potassium / Q000378:metabolism
D002712:Chlorides; D000001:Calcimycin; D004533:Egtazic Acid; D000109:Acetylcholine; D011188:Potassium