Adrenergic receptors on cerebral microvessels in control and parkinsonian subjects.

The binding of adrenergic ligands (3H-prazosin, 3H-clonidine, 3H-dihydroalprenolol) was studied on a preparation of cerebral microvessels in the prefrontal cortex and putamen of control and Parkinsonian subjects. The adrenergic receptor density in microvessels of control patients was less than 0.5% and 3.3% respectively of the total binding. A significant decrease in the number of alpha-1 binding sites was observed on microvessels in the putamen of patients with Parkinson's disease.