Dopamine receptors

Effects of chronic L-dopa and bromocriptine treatment in an animal model of Parkinson's disease

M. B. Schneider, L. C. Murrin, Ronald Pfeiffer, J. D. Deupree

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Male albino rats received a stereotaxic injection of 6-hydroxydopamine (6-OHDA) into the right substantia nigra. Animals demonstrating contralateral rotations 2 weeks postoperatively with apomorphine (0.5 mg/kg i.p.) were treated with L-Dopa (55 mg/kg i.p.), bromocriptine (2 mg/kg i.p.), or polyethylene glycol (vehicle) every 12 h for 30 days. Striatal dopamine (DA) receptors were analyzed by Scatchard plot using 3H-spiroperidol (3H-SP) as ligand. 3,4-Dihydroxyphenylacetic acid (DOPAC) and DA were measured by use of high pressure liquid chromatography. 6-OHDA lesions produced a supersensitivity in striatal DA receptors. Chronic L-Dopa or bromocriptine treatment reversed this supersensitivity. Neither lesion nor drug treatment alone or together produced a significant change in affinity (K(D)) for 3H-SP. Drug treatment alone also had no effect on B(max). DA and DOPAC levels were reduced by greater than 98% in lesioned striata. Neither drug treatment affected DA or DOPAC levels as compared with controls. These results indicate that chronic administration of either bromocriptine or L-Dopa will reverse the DA receptor denervation supersensitivity in striatum seen following 6-OHDA lesion. This reversal may play a role in the clinical changes seen in Parkinson's disease patients following chronic use of these drugs.

Original languageEnglish (US)
Pages (from-to)247-257
Number of pages11
JournalClinical Neuropharmacology
Volume7
Issue number3
StatePublished - 1984
Externally publishedYes

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Dopamine Agents
Bromocriptine
Oxidopamine
Dopamine Receptors
Levodopa
Parkinson Disease
Animal Models
Corpus Striatum
Spiperone
Dopamine
Pharmaceutical Preparations
3,4-Dihydroxyphenylacetic Acid
Acids
Apomorphine
Denervation
Substantia Nigra
Therapeutics
High Pressure Liquid Chromatography
Ligands
Injections

ASJC Scopus subject areas

  • Clinical Neurology
  • Pharmacology (medical)
  • Neuroscience(all)
  • Pharmacology, Toxicology and Pharmaceutics(all)

Cite this

Dopamine receptors : Effects of chronic L-dopa and bromocriptine treatment in an animal model of Parkinson's disease. / Schneider, M. B.; Murrin, L. C.; Pfeiffer, Ronald; Deupree, J. D.

In: Clinical Neuropharmacology, Vol. 7, No. 3, 1984, p. 247-257.

Research output: Contribution to journalArticle

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