Since dopamine (DA) was discovered as an essential neurotransmitter, with a profound
impact on motor control, memory, and behavioral impulses, the pathogenesis of several …

Patients with Parkinson's disease (PD) in long-term levodopa therapy often complain of
worsening of motor symptoms in the afternoon and evening. The pathophysiology of this …

An automated analytical procedure is described for the parallel determination of l-3, 4-
dihydroxyphenylalanine (levodopa, l-dopa, LD) and the analogous hydrazine compound …

In this study levodopa (L-DOPA), carbidopa (C-DOPA) and their metabolites were resolved
from other endogenous components present in human plasma and urine and determined …

Background: Antiparkinsonian comedication and/or altered gastrointestinal motility and
absorption influence plasma levels of levodopa. Another putative factor may represent body …

Exogenous application of levodopa is conventionally used to equalize the striatal dopamine
deficit in idiopathic Parkinson's disease (PD). The stimulation of endogenous biosynthesis of …

We could identify the MPTP-like compound and isoquinoline derivative N-methyl-
norsalsolinol (2-MDTIQ) in cerebrospinal fluid (CSF) of patients with Parkinson's disease …

An ion-pair reversed-phase liquid chromatographic method for the simultaneous
determination of levodopa, 3-O-methyldopa, 3, 4-dihydroxyphenylacetic acid, homovanillic …

We could quantify the tetrahydroisoquinoline derivative salsolinol in urine of patients with
Parkinson's disease and normal control subjects by means of high performance liquid …

Several lines of evidence suggest that endogenous and exogenous toxins may play a major
role in the pathogenesis of Parkinson's disease (PD). In vivo aromatic β‐carbolines, like …