Meyer J S, Welch K M, Deshmukh V D, Perez F I, Jacob R H, Haufrect D B, Mathew N T, Morrell R M
J Am Geriatr Soc. 1977 Jul;25(7):289-98. doi: 10.1111/j.1532-5415.1977.tb00640.x.
Ten patients with severe dementia due to Alzheimer's disease (AD) or multi-infarct dementia (MID) or both, were treated with the precursor amino acids of the neurotransmitters serotonin and dopamine. The precursor amino acids (PAA) were given orally in a preparation that included tyrosine (4 gm daily) and 5-hydroxy-tryptophan (5-HTP) (800 mg daily), plus carbidopa (100 mg daily) as an aromatic amino-acid decarboxylase inhibitor. Diagnosis was established by an electroencephalogram, brain scan, computerized axial tomographic scan, and in one case by necropsy findings. Serial clinical evaluations and measurements of neuropsychologic function were performed. Levels of homovanillic acid (HVA) and 5-hydroxyindole-acetic acid (5-HIAA) were determined before and after administration of probenecid. Side effects of the PAA therapy were diarrhea, drowsiness, nausea, vomiting and agitation, all of which were controlled by reducing the dosage. One patient with MID and one with AD+MID showed clinical and psychologic improvement, but the others did not improve. Analysis of the cerebrospinal fluid for HVA and 5-HIAA before and after the probenecid test indicated some improvement in the metabolic turnover of these acid metabolites of serotonin and dopamine after administration of their precursor amino acids.
十名患有由阿尔茨海默病（AD）或多发性梗死性痴呆（MID）或两者导致的重度痴呆症患者，接受了神经递质血清素和多巴胺的前体氨基酸治疗。前体氨基酸（PAA）通过一种制剂口服给药，该制剂包含酪氨酸（每日4克）和5-羟色氨酸（5-HTP）（每日800毫克），外加卡比多巴（每日100毫克）作为芳香族氨基酸脱羧酶抑制剂。诊断通过脑电图、脑部扫描、计算机断层扫描确立，其中一例通过尸检结果确诊。进行了系列临床评估和神经心理功能测量。在服用丙磺舒前后测定了高香草酸（HVA）和5-羟吲哚乙酸（5-HIAA）的水平。PAA治疗的副作用包括腹泻、嗜睡、恶心、呕吐和激动，所有这些副作用通过减少剂量得到控制。一名患有MID的患者和一名患有AD + MID的患者显示出临床和心理改善，但其他患者没有改善。丙磺舒试验前后对脑脊液中HVA和5-HIAA的分析表明，在给予其前体氨基酸后，血清素和多巴胺的这些酸性代谢物的代谢周转率有一定改善。
