PMID: 9523592Apr 2, 1998Paper

Biotransformation of L-DOPA to dopamine in the substantia nigra of freely moving rats: effect of dopamine receptor agonists and antagonists

Journal of Neurochemistry
Sophie SarreYvette Michotte

Abstract

We investigated the effects of continuous intranigral perfusion of dopamine D1 and D2 receptor agonists and antagonists on the biotransformation of locally applied L-DOPA to dopamine in the substantia nigra of freely moving rats by means of in vivo microdialysis. The "dual-probe" mode was used to monitor simultaneously changes in extracellular dopamine levels in the substantia nigra and the ipsilateral striatum. Intranigral perfusion of 10 microM L-DOPA for 20 min induced a significant 180-fold increase in extracellular nigral dopamine level. No effect of the intranigral L-DOPA administration was observed on dopamine levels in the ipsilateral striatum, suggesting a tight control of extracellular dopamine in the striatum after enhanced nigral dopamine levels. Continuous nigral infusion with the D1 receptor agonist CY 208243 (10 microM) and with the D2 receptor agonist quinpirole at 10 microM (a nonselective concentration) attenuated the L-DOPA-induced increase in dopamine in the substantia nigra by 85 and 75%, respectively. However, perfusion of the substantia nigra with a lower concentration of quinpirole (1 microM) and the D1 antagonist SCH 23390 (10 microM) did not affect the nigral L-DOPA biotransformation. The D2 antagonist...Continue Reading

Citations

Apr 10, 2007·Journal of Neural Transmission·J P M Finberg, O Sader-Mazbar
May 31, 2001·Archiv der Pharmazie·O A el-Sayed, H Y Aboul-Enein
Nov 5, 2021·Nature·Patricia González-RodríguezD James Surmeier

❮ Previous
Next ❯

Related Concepts

Related Feeds

Basal Ganglia

Basal Ganglia are a group of subcortical nuclei in the brain associated with control of voluntary motor movements, procedural and habit learning, emotion, and cognition. Here is the latest research.