Modulation of K+ channel currents by serum amineoxidase in neurons.
The influence of bovine serum amineoxidase (SAO), a circulating copper-enzyme, on neuronal K+ channels is described. Bovine SAO enhanced K+ channel currents in N1E-115 neuroblastoma cells in a time-dependent manner. Unlike ceruloplasmin (another copper-protein, shown as depolarizing factor in neurons), SAO had no effect on resting potential of neurons. However, pretreatment of cells with SAO inhibited ceruloplasmin-induced membrane depolarization. Although ceruloplasmin alone inhibited K+ channel currents, it further enhanced K+ channel currents in the presence of SAO. Therefore, SAO may be another endogenous modulator of neuronal K+ channels with effect and mechanisms different from those of ceruloplasmin.
Wu
L
L
Department of Physiology, Université de Montréal, Québec, Canada.
Mateescu
M A
MA
Wang
X T
XT
Mondovi
B
B
Wang
R
R
D006631:Amine Oxidase (Copper-Containing); D000818:Animals; D002417:Cattle; D002460:Cell Line; D002570:Ceruloplasmin / Q000494:pharmacology; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D008954:Models, Biological; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism*; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000097:blood / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects* / Q000378:metabolism*
D015221:Potassium Channels; D002570:Ceruloplasmin; D006631:Amine Oxidase (Copper-Containing); D000587:Oxidoreductases Acting on CH-NH Group Donors