Effect of long-term parenteral administration of empty and L-Dopa-loaded liposomes on the turnover of dopamine and its metabolites in the striatum of mice with experimental Parkinson's syndrome

It is found that the dose of L-Dopa required for correction of dopamine metabolism in experimental Parkinson's syndrome in C57B1/6 mice can be reduced 10-fold when the preparation is incorporated into small unilamellar liposomes (60 nm) composed from egg yolk phosphatidylcholine and cholesterol (7:3). High-performance liquid chromatography shows that a 14-day treatment with both L-Dopa incorporated into liposomes (5 mg/kg) and free L-Dopa (50 mg/kg) equally increases the content of dopamine and homovanillic acid and their ratio in mouse striatum. The content of dihydroxyphenylacetic acid markedly increases after administration of free L-Dopa.