Chronic treatment with nicotine or potassium attenuates depolarisation-evoked noradrenaline release from the human neuroblastoma SH-SY5Y.
Chronic treatment, of SH-SY5Y cells, with KCl (20 mM) for 4 days decreased 100 mM KCl-evoked noradrenaline (NA) release by 50% and nicotine (100 microM)-evoked NA release by 55%. Pretreatment with the L-type calcium channel antagonist, nifedipine, prevented this inhibitory effect of chronic exposure to 20 mM KCl on NA release. In contrast pretreatment with 10 microM nicotine for 4 days had no effect on 100 mM KCl -evoked secretion and decreased nicotinic -evoked NA release by only 25%. Inclusion of nifedipine prevented the inhibition of NA release by chronic nicotine treatment. These data are discussed in relation to effects of chronic moderate, depolarisation by either K(+) or nicotine on influx of Ca(2+) via L-type voltage sensitive calcium channels.
Agis-Torres
Angel
A
Sección Departamental de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain. aagisto@farm.ucm.es
Ball
Stephen G
SG
Vaughan
Peter F T
PF
D005731:Ganglionic Stimulants / Q000494:pharmacology*; D006801:Humans; D008564:Membrane Potentials / Q000187:drug effects; D009447:Neuroblastoma / Q000378:metabolism; D009538:Nicotine / Q000494:pharmacology*; D009638:Norepinephrine / Q000096:biosynthesis*; D011189:Potassium Chloride / Q000494:pharmacology*; D013997:Time Factors; D014407:Tumor Cells, Cultured; D014701:Veratridine / Q000494:pharmacology
D005731:Ganglionic Stimulants; D011189:Potassium Chloride; D009538:Nicotine; D014701:Veratridine; D009638:Norepinephrine