Cholinergic receptors regulate a voltage-insensitive but Na+-dependent calcium influx pathway in salivary acinar cells.
The calcium-sensitive fluorescent probe, quin 2, was employed to investigate the cholinergic receptor regulation of cytosolic free calcium concentration [( Ca2+]i) in isolated rat submandibular acinar cells. Cholinergic receptor stimulation results in a marked and sustained elevation [Ca2+]i. The major component of this response is shown to be due to activation of a calcium influx pathway. There is no evidence in K+-depolarized cells of any voltage-gated calcium influx. Acetylcholine failed to activate the calcium influx pathway in cells bathed in Na+-free solutions. The cholinergic receptors thus regulate a voltage-insensitive but Na+-dependent transport system for calcium entry in submandibular acinar cells.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D004594:Electrophysiology; D008297:Male; D008536:Meglumine / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D009994:Osmolar Concentration; D051381:Rats; D011950:Receptors, Cholinergic / Q000502:physiology*; D012964:Sodium / Q000494:pharmacology*; D013363:Submandibular Gland / Q000166:cytology / Q000378:metabolism*
D011950:Receptors, Cholinergic; D008536:Meglumine; D012964:Sodium; D000109:Acetylcholine; D002118:Calcium