We used intrastriatal microdialysis to study the effect of pergolide, a D1/D2 dopamine (DA) receptor agonist on biotransformation of exogenous L-DOPA in hemi-Parkinsonian rats. DA and metabolites were assayed by microbore liquid chromatography. Pergolide (50 micrograms/kg, i.p.) caused a 67% and 87% decrease in striatal EC levels of DA in intact and denervated striatum respectively. In intact striatum but not in denervated striatum, pergolide decreased EC levels of 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) (53% and 42% decrease, respectively). L-DOPA (100 mg/kg, i.p.) produced significant increase in EC levels of DA, DOPAC and HVA in intact and denervated striatum with and without local perfusion of 10(-4) M pergolide. In denervated striatum, L-DOPA-induced DA increase was significantly higher in rats with pergolide. Our results suggest that, in an animal model of Parkinson's disease, pergolide in association with L-DOPA favors the restoration of striatal EC DA levels.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s007020050147 | DOI Listing |
Brain Commun
January 2025
Department of Clinical Medicine, Aarhus University Hospital, Aarhus N, 8200 Aarhus, Denmark.
Asymmetric dopaminergic degeneration of the striatum is a characteristic feature of Parkinson's disease, associated with right-left asymmetry in motor function. As such, studying asymmetry provides insights into progressive neurodegeneration between cerebral hemispheres. Given the impact of Lewy pathology on various neurotransmitter systems beyond the dopaminergic, it may be that other neuronal systems in the predominantly affected hemisphere are similarly affected.
View Article and Find Full Text PDFJ Neuroimaging
January 2025
Department of Nuclear Medicine, Seoul National University Bundang Hospital, Seongnam-si, Republic of Korea.
Background And Purpose: We investigated the relationship between serotonergic and dopaminergic specific binding transporter ratios (SBRs) over 4 years in Parkinson's disease (PD) patients. We assessed serotonergic innervation's potential compensatory role for dopaminergic denervation, association with PD symptoms, and involvement in the development of levodopa-induced dyskinesia (LID).
Methods: SBRs of the midbrain and striatum were evaluated from [I-123] N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane SPECT images at baseline and after 4 years.
Eur J Neurol
January 2025
Department of Neurosurgery and Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Jiangsu, China.
Exp Neurol
January 2025
Department of Molecular and Translational Medicine University of Brescia, Brescia, Italy. Electronic address:
Parkinson's disease (PD) is characterized by the loss of nigrostriatal dopaminergic neurons and the presence of Lewy bodies (LB), intraneuronal inclusions mainly composed of α-synuclein (α-Syn) fibrils. Compelling evidence supports that, in PD brains, synapses are the sites where neurodegeneration initiates several years before the manifestation of motor symptoms. Furthermore, the amount of α-Syn deposited at synaptic terminals is several orders greater than that constituting LB.
View Article and Find Full Text PDFEfforts to develop disease-modifying treatments for Parkinson's disease (PD) have been hindered by the lack of animal models replicating all hallmarks of PD and the insufficient attention to extra-nigrostriatal regions pathologically critical for the prodromal appearance of non-motor symptoms. Among PD models, 6-hydroxydopamine (6-OHDA) infusion in mice has gained prominence since 2012, primarily focusing on the nigrostriatal region. This study characterized widespread tyrosine hydroxylase-positive neuron and fiber loss across the brain following a unilateral 6-OHDA (20 μg) infusion into the dorsal striatum.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!