Adenosine 2A receptor availability in dyskinetic and nondyskinetic patients with Parkinson disease
Objective: To research striatal adenosine A2A receptor availability in patients with Parkinson disease (PD) with and without levodopa-caused dyskinesias (Covers). While supplying effective respite from the motor signs and symptoms of PD, chronic levodopa me is connected with growth and development of Covers. A2A receptors are expressed around the physiques of indirect path medium spiny striatal neurons as well as on dopamine terminals and lead to modulating dopamine transmission. A2A antagonists have antiparkinsonian activity by boosting levodopa effectiveness. We aimed to review A2A receptor availability in patients with PD with and without Covers using PET and [¹¹C]SCH442416, an A2A antagonist.
Methods: Six patients with PD with and 6 without Covers were studied withdrawn 12 hrs from medication. Their PET findings were in contrast to 6 age-matched healthy controls. Using spectral analysis, [¹¹C]SCH442416 regional volumes of distribution (V(T)) were computed for that caudate, putamen, and thalamus and binding potentials (BP(ND)) reflecting the number of specific:nonspecific uptake were compared between groups.
Results: A2A binding within the caudate and putamen of subjects with SCH-442416 PD with Covers was far greater (p = .026 and p = .036, correspondingly) compared to subjects with PD without Covers, which lay inside the control range. Thalamic A2A availability was similar for those 3 groups.
Conclusion: Patients with PD with Covers show elevated A2A receptor availability within the striatum. This finding works with altered adenosine transmission playing a job in Covers and offers a rationale for any trial of A2A receptor agents in treating these motor complications.