Melamed E, Globus M, Mildworf B
J Neurol Neurosurg Psychiatry. 1986 Nov;49(11):1301-4. doi: 10.1136/jnnp.49.11.1301.
In ten Parkinsonians who developed dose-related response fluctuations under long-term levodopa therapy, regional cerebral blood flow (rCBF) and plasma levodopa levels were measured simultaneously, once during an "off" phase and again at an "on" stage of clinical benefit induced by a single oral dose of levodopa. Although plasma levodopa increased threefold during the "on" period, rCBF and the degree of its reduction from normal age-matched control values remained unchanged and similar to those in the "off" phase. Study suggests that the rCBF decreases in Parkinson's disease are unaffected by levodopa and are not due to deficient dopaminergic neurotransmission in the brain.
在10名长期接受左旋多巴治疗出现剂量相关反应波动的帕金森病患者中，在“关”期和单次口服左旋多巴诱导的临床获益“开”期分别同时测量了局部脑血流量（rCBF）和血浆左旋多巴水平。尽管在“开”期血浆左旋多巴增加了两倍，但rCBF及其相对于年龄匹配正常对照值的降低程度保持不变，且与“关”期相似。研究表明，帕金森病中的rCBF降低不受左旋多巴影响，并非由于大脑中多巴胺能神经传递不足所致。
