Both 3,4-dihydroxyphenylalanine and dopamine releases are regulated by Ca2+-induced Ca2+ releasing system in rat striatum

Neurosci Lett. 2004 May 27;362(3):244-8. doi: 10.1016/j.neulet.2004.03.031.

Abstract

To clarify the striatal Ca2+-dependent monoaminergic exocytosis mechanisms, this study determined the effects of the Ca2+-induced Ca2+ releasing system (CICR), containing inositol-trisphosphate-receptor (IP3R) and ryanodine-receptor (RyR), on striatal releases of dopamine and its precursor, 3,4-dihydroxyphenylalanine (DOPA), using microdialysis. The basal dopamine release is regulated by IP3R but not by RyR, whereas basal DOPA release does not require CICR. The K+-evoked releases of DOPA and dopamine were enhanced by IP3R agonist, whereas RyR agonist reduced it. Additionally, inhibition of dopamine release induced by RyR hyperactivation was prevented by inhibition of L-type voltage-sensitive Ca2+-channel activity. These present results suggest that CICR-associated regulation of striatal releases of DOPA and dopamine is restrictive during the resting stage, whereas CICRs play an important role as a reserve mechanism of exocytosis of striatal DOPA and dopamine during the hyperexcitable stage.

Publication types

  • Comparative Study

MeSH terms

  • Adenosine / analogs & derivatives*
  • Adenosine / pharmacology
  • Analysis of Variance
  • Animals
  • Calcium / metabolism*
  • Calcium Channels / drug effects
  • Calcium Channels / physiology
  • Chromatography, High Pressure Liquid / methods
  • Corpus Striatum / drug effects
  • Corpus Striatum / metabolism*
  • Dopamine / metabolism*
  • Dose-Response Relationship, Drug
  • Electrochemistry / methods
  • Inositol 1,4,5-Trisphosphate / pharmacology
  • Inositol 1,4,5-Trisphosphate Receptors
  • Levodopa / pharmacology
  • Macrocyclic Compounds
  • Male
  • Microdialysis / methods
  • Oxazoles / pharmacology
  • Potassium / pharmacology
  • Rats
  • Rats, Wistar
  • Receptors, Cytoplasmic and Nuclear / drug effects
  • Receptors, Cytoplasmic and Nuclear / physiology
  • Ruthenium Red / pharmacology
  • Ryanodine / pharmacology
  • Ryanodine Receptor Calcium Release Channel / drug effects
  • Ryanodine Receptor Calcium Release Channel / physiology
  • Time Factors
  • Verapamil / pharmacology

Substances

  • Calcium Channels
  • Inositol 1,4,5-Trisphosphate Receptors
  • Macrocyclic Compounds
  • Oxazoles
  • Receptors, Cytoplasmic and Nuclear
  • Ryanodine Receptor Calcium Release Channel
  • xestospongin A
  • Ruthenium Red
  • adenophostin A
  • Ryanodine
  • Levodopa
  • Inositol 1,4,5-Trisphosphate
  • Verapamil
  • Adenosine
  • Potassium
  • Calcium
  • Dopamine