The Role and Development of the Antagonist of Adenosine A2A in Parkinson’s Disease

Adenosine is a neuromodulator that regulates the body’s response to dopamine and another neurotransmitter in the brain that is responsible for motoric, emotion, learning, and memory function. Adenosine is a G-protein-coupled receptor and has four subtypes, which are A 1, A 2A , A 2B , and A 3 . Adenosine A 2A is located in the striatum of the brain. Antagonist interferes with GABA releasing, modulates acetyl-choline and releases dopamine, and also facilitates dopamine receptor’s signaling. Therefore, it can reduce motoric symptoms in Parkinson’s disease. Adenosine A 2A antagonist is also believed to have neuroprotective effects. Several compounds have been reported and have undergone clinical test as selective adenosine A 2A antagonists, including istradefylline, preladenant, tozadenant, vipadenant, ST-1535, and SYN-115. Nonselective adenosine A 2A antagonists from natural compounds are caffeine and theophylline. ,