The effect of intrastriatal injection of liposome-entrapped tyrosinase on the dopamine levels in the rat brain.
Parkinson's disease is a neurodegenerative disorder which is mainly characterized by degeneration of the dopaminergic cells in the nigro-striatal system. Due to a lowered L-tyrosine 3-monooxygenase activity, L-tyrosine is not sufficiently transformed to L-DOPA. To date the most common therapy is the administration of the dopamine precursor L-DOPA, with severe collateral effects. Therefore, the substitution of the lacking tyrosine hydroxylase with tyrosinase might be a novel therapeutical approach that would generate specifically L-DOPA from L-tyrosine. We present here evidence that stereotaxic injection of liposome-entrapped tyrosinase is able to significatively increase the levels of dopamine in the rat brain. The catecholamines L-DOPA, dopamine, L-epinephrine, L-norepinephrine were extracted by acid treatment from the brains and detected by HPLC.
Amicarelli
F
F
Department of Basic and Applied Biology, University of L'Aquila, Coppito-L'Aquila, Italy.
Gasbarri
A
A
Masciocco
L
L
Pompili
A
A
Pacitti
C
C
Carlucci
G
G
Palumbo
G
G
Miranda
M
M
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004295:Dihydroxyphenylalanine / Q000096:biosynthesis; D004298:Dopamine / Q000096:biosynthesis*; D004337:Drug Carriers; D004353:Drug Evaluation, Preclinical; D004837:Epinephrine / Q000096:biosynthesis; D008081:Liposomes; D008297:Male; D014442:Monophenol Monooxygenase / Q000008:administration & dosage / Q000494:pharmacology*; D009638:Norepinephrine / Q000096:biosynthesis; D010300:Parkinson Disease / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013238:Stereotaxic Techniques
D004337:Drug Carriers; D008081:Liposomes; D004295:Dihydroxyphenylalanine; D014442:Monophenol Monooxygenase; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine