Abi-Dargham A, Gil R, Krystal J, Baldwin R M, Seibyl J P, Bowers M, van Dyck C H, Charney D S, Innis R B, Laruelle M
Department of Psychiatry, Yale University, New Haven, Conn., USA.
Am J Psychiatry. 1998 Jun;155(6):761-7. doi: 10.1176/ajp.155.6.761.
The authors previously observed an increase in striatal dopamine transmission following amphetamine challenge in 15 untreated patients with schizophrenia compared to 15 matched healthy subjects. The purpose of this study was to replicate this finding in a new cohort of schizophrenic patients and healthy subjects.
Fifteen patients with schizophrenia and 15 healthy subjects matched for age, gender, ethnicity, and parental socioeconomic status were recruited for this study. Patients fulfilled DSM-IV criteria for schizophrenia, had no history of alcohol or substance abuse or dependence, and were neuroleptic free for a minimum of 21 days. Amphetamine-induced dopamine release was assessed by the reduction in dopamine D2 receptor availability induced by an acute amphetamine challenge (0.3 mg/kg, intravenous bolus). Reduction in D2 receptor availability was measured with single photon emission computed tomography and the D2 receptor radiotracer [123I]IBZM.
No differences were observed between patients with schizophrenia and the comparison group in D2 receptor availability at baseline. Patients with schizophrenia exhibited a significantly larger reduction in D2 receptor availability following acute amphetamine challenge than the comparison group. In this study, the effect size was smaller than in the first study. Excess dopamine release following amphetamine was associated with transient emergence or worsening of positive symptoms.
In this new cohort of subjects the authors replicated their initial observation of a dysregulation of striatal dopamine release in schizophrenia.
作者之前观察到，与15名匹配的健康受试者相比，15名未经治疗的精神分裂症患者在接受苯丙胺激发试验后纹状体多巴胺传递增加。本研究的目的是在一组新的精神分裂症患者和健康受试者中重复这一发现。
本研究招募了15名精神分裂症患者和15名在年龄、性别、种族及父母社会经济地位方面相匹配的健康受试者。患者符合精神分裂症的DSM-IV标准，无酒精或药物滥用或依赖史，且至少21天未使用抗精神病药物。通过急性苯丙胺激发试验（0.3mg/kg，静脉推注）诱导的多巴胺D2受体可用性降低来评估苯丙胺诱导的多巴胺释放。使用单光子发射计算机断层扫描和D2受体放射性示踪剂[123I]IBZM测量D2受体可用性的降低。
精神分裂症患者与对照组在基线时的D2受体可用性无差异。与对照组相比，精神分裂症患者在急性苯丙胺激发试验后D2受体可用性的降低幅度明显更大。在本研究中，效应大小比第一项研究小。苯丙胺后多巴胺释放过多与阳性症状的短暂出现或加重有关。
在这组新的受试者中，作者重复了他们最初的观察结果，即精神分裂症患者纹状体多巴胺释放失调。
