Amin F, Davidson M, Kahn R S, Schmeidler J, Stern R, Knott P J, Apter S
Psychiatry Service, Houston VA Medical Center, TX 77030, USA.
Schizophr Bull. 1995;21(1):53-66. doi: 10.1093/schbul/21.1.53.
Under fasting conditions, the dopamine (DA) metabolite homovanillic acid (HVA) in plasma originates mainly from central DA neurons or from central and peripheral noradrenergic (NA) neurons. The latter source contributes, in addition to HVA, the norepinephrine metabolites, for example, 3-methoxy-4-hydroxyphenylglycol (MHPG). It has been shown in primates that the association between HVA and MHPG in plasma or urine under varying rates of NA metabolism can be used to obtain an estimate of the central DA neuronal contribution of HVA to plasma or urine. This estimate is called the central dopaminergic index (CDI). Two studies presented here examine the applicability of this model in schizophrenia patients. The results were consistent with the proposed model and suggested that only about 30 percent of the total plasma HVA concentrations in our patients were derived from central DA neurons. A convenient modification of this model is proposed for future studies. Since the CDI of plasma HVA is not likely to be confounded by NA activity, this tool may prove useful in disentangling the roles played by the DA and NA systems in schizophrenia.
在禁食条件下，血浆中的多巴胺（DA）代谢产物高香草酸（HVA）主要来源于中枢DA神经元或中枢及外周去甲肾上腺素能（NA）神经元。除了HVA，后一种来源还会产生去甲肾上腺素代谢产物，例如3-甲氧基-4-羟基苯乙二醇（MHPG）。在灵长类动物中已表明，在不同的NA代谢速率下，血浆或尿液中HVA与MHPG之间的关联可用于估算HVA对血浆或尿液的中枢DA神经元贡献。这个估算值称为中枢多巴胺能指数（CDI）。本文介绍的两项研究检验了该模型在精神分裂症患者中的适用性。结果与所提出的模型一致，表明在我们的患者中，血浆总HVA浓度中只有约30%来源于中枢DA神经元。为未来的研究提出了对该模型的一种简便修改方法。由于血浆HVA的CDI不太可能受到NA活性的干扰，这个工具可能在厘清DA和NA系统在精神分裂症中所起的作用方面证明是有用的。
