Nicotinic acetylcholine receptors in human neuroblastoma (SH-SY5Y) cells.
Whole-cell patch-clamp recordings were used to investigate nicotinic acetylcholine receptors (nAChRs) in the human neuroblastoma cell line, SH-SY5Y. Acetylcholine, nicotine and the neuronal nAChR agonist dimethylphenylpiperazinium iodide (DMPP), but not muscarine, all evoked inward currents in the cells (voltage-clamped at -60 mV). DMPP's actions were concentration- and voltage-dependent, and were antagonised by the neuronal nAChR antagonist mecamylamine (1-3 microM). Atropine was ineffective at 0.1 microM, but at 1 microM caused significant reductions in current amplitudes. Pre-incubation of cells with 2 microM alpha-cobratoxin had no effect on the actions of DMPP, and inward currents could also be induced when extracellular NaCl was replaced with CaCl2. DMPP also reversibly depolarized SH-SY5Y cells. These findings clearly identify nAChRs in SH-SY5Y cells, and provide two possible mechanisms by which receptor activation may lead to noradrenaline release, namely by triggering Ca2+ influx through the nAChR itself or by opening voltage-gated Ca2+ channels.
Gould
J
J
Department of Pharmacology, Leeds University, UK.
Reeve
H L
HL
Vaughan
P F
PF
Peers
C
C
D000109:Acetylcholine / Q000494:pharmacology; D001285:Atropine / Q000494:pharmacology; D003039:Cobra Neurotoxin Proteins / Q000494:pharmacology; D004246:Dimethylphenylpiperazinium Iodide / Q000494:pharmacology; D006801:Humans; D009447:Neuroblastoma / Q000378:metabolism*; D009538:Nicotine / Q000494:pharmacology; D011978:Receptors, Nicotinic / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D003039:Cobra Neurotoxin Proteins; D011978:Receptors, Nicotinic; D004246:Dimethylphenylpiperazinium Iodide; C025154:alpha-cobratoxin; D009538:Nicotine; D001285:Atropine; D000109:Acetylcholine