Interaction between dopamine and phospholipids. Studies of the substantia nigra in Parkinson disease patients.

Interaction between dopamine and phospholipids was studied in the substantia nigra of ten patients with Parkinson disease and nine control subjects. There were no differences in the total content of phospholipids. However, in parkinsonian patients without previous levodopa treatment, the amount of sphingomyelin was increased and the amount of phosphatidylethanolamine and phosphatidylcholine decreased. Levodopa treatment corrected these values to the level of controls, whereas the amount of phosphatidylserine was decreased. It is concluded that changes in phospholipids are reflections of the deficiency of dopamine and loss of dopaminergic neurons in the substantia nigra of patients with Parkinson disease.