George S, Binkley K, Seeman P
J Neural Transm Suppl. 1983;18:149-56.
Of the several dopamine-sensitive sites in the brain, the one that most correlates with psychomotor behaviour is the D2 receptor. This receptor has two states. The D2Hi state is characterized by its nM affinity for dopamine. The D2Lo state is typified by its microM affinity for dopamine. Neuroleptics have the same affinity (50 pM for spiperone) for both states. Guanine nucleotides convert most, if not all, of the D2Hi sites into D2Lo sites. Any D2Hi sites which are insensitive to GTP, if such exist, may be separate D4 sites. In addition to the binding of 3H-spiperone being higher in post-mortem schizophrenic brains, the proportions of the D2 receptor in the D2Hi state appear to be less in preliminary data on the schizophrenic brain.
在大脑中几个对多巴胺敏感的位点中，与精神运动行为关联最密切的是D2受体。该受体有两种状态。D2Hi状态的特点是对多巴胺具有纳摩尔亲和力。D2Lo状态的典型特征是对多巴胺具有微摩尔亲和力。抗精神病药物对这两种状态具有相同的亲和力（对螺哌隆而言为50皮摩尔）。鸟嘌呤核苷酸能将大部分（如果不是全部的话）D2Hi位点转化为D2Lo位点。任何对鸟苷三磷酸（GTP）不敏感的D2Hi位点（如果存在的话）可能是独立的D4位点。除了在精神分裂症患者死后大脑中3H-螺哌隆的结合量更高外，在精神分裂症大脑的初步数据中，处于D2Hi状态的D2受体比例似乎更低。
