ANEPIII, a new recombinant neurotoxic polypeptide derived from scorpion peptide, inhibits delayed rectifier, but not A-type potassium currents in rat primary cultured hippocampal and cortical neurons.
A new recombinant neurotoxic polypeptide ANEPIII (BmK ANEPIII) derived from Scorpion peptide, which was demonstrated with antineuroexcitation properties in animal models, was examined for its action on K+ currents in primary cultured rat hippocampal and cortical neurons using the patch clamp technique in the whole-cell configuration. The delayed rectifier K+ current (I(k)) was inhibited by externally applied recombinant BmK ANEPIII, while the transient A-current (I(A)) remained virtually unaffected. BmK ANEPIII 3 microM, reduced the delayed rectifier current by 28.2% and 23.6% in cultured rat hippocampal and cortical neurons, respectively. The concentration of half-maximal block was 155.1 nM for hippocampal neurons and 227.2 nM for cortical neurons, respectively. These results suggest that BmK ANEPIII affect K+ currents, which may lead to a reduction in neuronal excitability.
Li
Chun-Li
CL
Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang 110016, PR China.
Zhang
Jing-Hai
JH
Yang
Bao-Feng
BF
Jiao
Jun-Dong
JD
Wang
Ling
L
Wu
Chun-Fu
CF
D000818:Animals; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects*; D051668:Delayed Rectifier Potassium Channels / Q000037:antagonists & inhibitors* / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000187:drug effects* / Q000378:metabolism; D024642:Potassium Channels, Voltage-Gated / Q000187:drug effects; D051381:Rats; D012604:Scorpion Venoms / Q000378:metabolism / Q000494:pharmacology*; D012605:Scorpions / Q000201:enzymology*
D051668:Delayed Rectifier Potassium Channels; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D012604:Scorpion Venoms; C058792:anti-epilepsy peptide, Buthrus martensii