Effect of metadoxine on striatal dopamine levels in C57 black mice

J Pharm Pharmacol. 1993 May;45(5):476-8. doi: 10.1111/j.2042-7158.1993.tb05579.x.


In the present study, we examined the effect of metadoxine on striatal levels of dopamine, 5-hydroxytryptamine (5-HT) and their metabolites in male C57 Black mice. Striatal content was assayed after systemic administration of metadoxine ranging from 1 micrograms kg-1 to 500 mg kg-1. Striatal dopamine increased 1 h after treatment with metadoxine (150 mg kg-1), but the most notable effect was obtained 24 h after the drug administration. At this time a plateau was reached; the two major metabolites of dopamine showed the same trend. Seven days after metadoxine administration, striatal dopamine approached the control values. Over the same time intervals, striatal 5-HT increased to a lesser extent and 5-hydroxy-indoleacetic acid did not differ significantly from controls. Striatal dopamine increased significantly at a dose of 250 micrograms kg-1 up to a dose of 1 mg kg-1 metadoxine; no further increment was observed between 1 and 500 mg kg-1 metadoxine. Administration of each component at doses equimolar to 1 mg metadoxine showed that pyridoxine produced only a mild increase in striatal dopamine compared with controls. We suggest that the metadoxine-induced striatal dopamine increase is obtained by increasing synthesis of dopamine.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Corpus Striatum / chemistry
  • Corpus Striatum / drug effects*
  • Corpus Striatum / metabolism*
  • Dopamine / analysis
  • Dopamine / metabolism*
  • Dose-Response Relationship, Drug
  • Drug Combinations
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Pyridoxine / pharmacology*
  • Pyrrolidonecarboxylic Acid / pharmacology*
  • Serotonin / metabolism
  • Time Factors


  • Drug Combinations
  • Serotonin
  • metadoxine
  • Pyridoxine
  • Pyrrolidonecarboxylic Acid
  • Dopamine