^
Nissinen E; Nissinen H; Larjonmaa H; et al. The COMT inhibitor, entacapone, reduces levodopa-induced elevations in plasma homocysteine in healthy adult rats. J Neural Transm. September 2005, 112 (9): 1213–1221. PMID 15614425. doi:10.1007/s00702-004-0262-4.
^Giakoumaki SG, Roussos P, Bitsios P. Improvement of Prepulse Inhibition and Executive Function by the COMT Inhibitor Tolcapone Depends on COMT Val158Met Polymorphism. Neuropsychopharmacology. June 2008, 33 (13): 3058–3068. PMID 18536698. doi:10.1038/npp.2008.82.