l-dopa


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Related to l-dopa: levodopa, dopamine, Mucuna pruriens

l-dopa

(ĕl-dō`pə), drug used to alleviate some of the symptoms of Parkinson's diseaseParkinson's disease
or Parkinsonism,
degenerative brain disorder first described by the English surgeon James Parkinson in 1817. When there is no known cause, the disease usually appears after age 40 and is referred to as Parkinson's disease; a number of genes have
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, particularly trembling, rigidity, and slow movements; the drug is also called levodopa. Parkinson's disease results when the concentration of dopamine in the brain is depleted (see catecholaminecatecholamine
, any of several compounds occurring naturally in the body that serve as hormones or as neurotransmitters in the sympathetic nervous system. The catecholamines include such compounds as epinephrine, or adrenaline, norepinephrine, and dopamine.
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). Medical administration of dopamine itself is ineffective since that chemical apparently does not enter the brain from the blood. A metabolic precursor of dopamine, l-dopa does enter the brain via the bloodstream and is probably converted into dopamine there. Because there are many brain disorders with similar symptoms, many patients do not show any improvement when treated with the drug. Furthermore, virtually all patients on l-dopa experience side effects including nausea, loss of appetite, cardiac irregularities, and psychological changes.

L-dopa

[¦el ′dō·pə]
(pharmacology)
References in periodicals archive ?
Since sensitivity to catecholamines in the heart is increased in patients using L-Dopa, these agents, especially halothane, should be avoided in such patients.
A total number of 42 rats were used in this experiment, 21 days after the surgery, animals were randomly divided into three groups ( n = 14 each group): (a) sham group (sham-operated, treated with saline); (b) 6-OHDA group (6-OHDA-lesioned, also treated with saline); and (c) L-DOPA group (6-OHDA-lesioned, treated with L-DOPA).
L-Dopa is also used to control the changes in enzymes of myocardium and neurogenic injuries [2, 3].
Motor improvements were accompanied in the most favourable cases by withdrawal of the L-DOPA treatment [11, 12] and paralleled by increased [18F]DOPA uptake in PET studies [5, 13, 14], suggesting that motor improvements could not be regarded as placebo effect.
Table 1 Characteristics of patients with Parkinson's disease Sex Age mH Duration UPDRS UPDRS Medication (y) Y of PD (Y) (III) (I-IV) M 71 3 8 28 38 800MG L-DOPA M 63 2 3 15 16 700MG L-DOPA F 70 2.
Hinz gives L-dopa from the Mucuna pruriens bean from South America with a 40% L-dopa content.
Dessa forma, a administracao da L-DOPA associada a inibidores das descarboxilases (haja vista que tais inibidores nao atravessam a barreira hematoencefalica) melhora a biodisponibilidade da dopamina no sistema nervoso central, necessitando de doses menores, alem de reduzir efeitos indesejaveis [13-15].
Compared to 3-hydroxy-2-methylpyridine-4,5-dicarboxylate, DL-dopa, metanephrine, and phosphoguanidinoacetate, the fragmentation mode of L-dopa was matched more analogously to the observation of fragment ion in MS2 spectrum of m/z 198.
L-DOPA is a prodrug that, unlike dopamine, is able to cross the bloodbrain barrier.
Current treatment methods, such as L-dopa therapy, are focused only on relieving symptoms and delaying progression of the disease.
L-DOPA also eliminated the memory and learning deficits in these mice.