ATP-Sensitive Potassium Channels Regulate In Vivo Dopamine Release in Rat Striatum

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Author(s)

Abstract

ATP-sensitive K<SUP>+</SUP> channels (K<SUB>ATP</SUB>) are distributed in a variety of tissues including smooth muscle, cardiac and skeletal muscle, pancreatic β-cells and neurons. Since K<SUB>ATP</SUB> channels are present in the nigrostriatal dopamine (DA) pathway, the effect of potassium-channel modulators on the release of DA in the striatum of conscious, freely-moving rats was investigated. The extracellular concentration of DA was significantly decreased by the K<SUB>ATP</SUB>-channel opener (-)-cromakalim but not by diazoxide. (-)-Cromakalim was effective at 100 and 1000 μM concentrations, and the maximum decrease was 54% below baseline. <I>d</I>-Amphetamine significantly increased extracellular DA levels at the doses of 0.75 and 1.5 mg/kg, s.c. with a 770% maximum increase. (-)-Cromakalim had no effect on <I>d</I>-amphetamine-induced DA release, while glyburide, a K<SUB>ATP</SUB> blocker, significantly potentiated the effects of a low dose of <I>d</I>-amphetamine. These data indicate that K<SUP>+</SUP> channels present in the nigrostriatal dopaminergic terminals modulate basal release as well as evoked release of DA.

Journal

  • The Japanese Journal of Pharmacology

    The Japanese Journal of Pharmacology 79(1), 59-64, 1999-01

    The Japanese Pharmacological Society

References:  25

Codes

  • NII Article ID (NAID)
    10008194153
  • NII NACSIS-CAT ID (NCID)
    AA00691188
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    00215198
  • NDL Article ID
    4636916
  • NDL Source Classification
    ZS51(科学技術--薬学)
  • NDL Call No.
    Z53-D199
  • Data Source
    CJP  NDL  J-STAGE 
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