L-3,4-dihydroxyphenylalanine-induced hypersensitivity simulating features of denervation.

AUTOR(ES)

Tang, L C

RESUMO

The manner in which dyskinesia and intermittency of neurological control had emerged late in the therapy of Parkinsonism with L-3,4-dihydroxyphenylalanine (levodopa) had suggested to us that this drug can imprint on the brain a chemical memory of its passage. The majority of authors ascribed these events to denervation hypersensitivity caused by the nigral and other lesions of the disease. By feeding levodopa to mice, however, we induced a state that simulated denervations hypersensitivity, including hyperreaction to single injections of levodopa and increased dopamine-stimulated adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] activity in homogenates of caudate nuclei. These phenomena were not caused by actual denervation, because the hypersensitivity declined and disappeared some weeks after the dietary levodopa was stopped.

Documentos Relacionados

• THE EFFECTS OF RESERPINE, α-METHYLTYROSINE, AND L-3,4-DIHYDROXYPHENYLALANINE ON BRAIN TYROSINE TRANSAMINASE*
• L-3,4-dihydroxyphenylalanine (levodopa) lowers central nervous system S-adenosylmethionine concentrations in humans.
• Use of 3,4-Dihydroxyphenylalanine Oxidation in the Identification of Mycobacterium leprae
• Synthesis of l-3, 4-Dihydroxyphenylalanine from l-Tyrosine by Microorganisms
• Scoliosis in rats with experimentally-induced hemiparkinsonism: dependence upon striatal dopamine denervation.