Department of Neurology, St. Joseph Hospital, Berlin, Germany.
Int Rev Neurobiol. 2010;95:49-71. doi: 10.1016/B978-0-12-381326-8.00004-1.
Long-term daily repeated intake of traditional levodopa (L-dopa)/dopa decarboxylase inhibitor (DDI) formulations increases the homocysteine synthesis in plasma of Parkinson's disease patients with unforeseen consequences, like an augmented vulnerability for onset of concomitant non-motor symptoms. Homocysteine decrease may therefore be a future therapeutic challenge, which may be achieved by supplementation with certain vitamins or by combination of a catechol-O-methyltransferase (COMT) inhibitor with L-dopa/DDI administration. Monitoring of plasma homocysteine concentration may also serve as biomarker for the detoxification potential of endogenous, exogenous, and environmental toxins. These substrates may also accumulate in the nervous system, since homocysteine formation is associated with O-methylation which has a broad detoxification potential.
长期每日重复摄入传统左旋多巴（L-dopa）/多巴胺脱羧酶抑制剂（DDI）制剂会增加帕金森病患者血浆中同型半胱氨酸的合成，带来意想不到的后果，例如增加同时发生非运动症状的易感性。因此，降低同型半胱氨酸可能是未来的治疗挑战，可以通过补充某些维生素或与 L-dopa/DDI 给药联合使用儿茶酚-O-甲基转移酶（COMT）抑制剂来实现。血浆同型半胱氨酸浓度的监测也可以作为内源性、外源性和环境毒素解毒潜能的生物标志物。由于同型半胱氨酸的形成与具有广泛解毒潜能的 O-甲基化有关，这些底物也可能在神经系统中积累。
