Human Neurochemical Pathology Laboratory, Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada.
Synapse. 2010 Jun;64(6):417-20. doi: 10.1002/syn.20743.
We previously reported increased binding of (+)[11C]DTBZ (dihydrotetrabenazine), the vesicular monoamine transporter (VMAT2) positron emission tomography (PET) radioligand, in striatum of some methamphetamine users. This finding might be explained by stimulant-induced vesicular DA depletion resulting in decreased DA (+)[11C]DTBZ competition at VMAT2. In a prospective PET study, we now find that administration of an acute oral dose of amphetamine (0.4 mg/kg) to humans does not cause increased striatal (+)[11C]DTBZ binding but a slight 5% decrease. Our data suggest that a low amphetamine dose is unlikely to cause sufficient DA depletion to detect increased (+)[11C]DTBZ binding and that a higher dose might be required.
我们之前曾报道，一些甲基苯丙胺使用者的纹状体中，（+）[11C]DTBZ（二氢四苯并嗪）的结合增加，（+）[11C]DTBZ 是囊泡单胺转运蛋白（VMAT2）正电子发射断层扫描（PET）放射性配体。这一发现可能是由于兴奋剂诱导的囊泡 DA 耗竭，导致 DA 减少，从而减少了 DA（+）[11C]DTBZ 在 VMAT2 上的竞争。在一项前瞻性 PET 研究中，我们现在发现，给人类服用急性口服安非他命（0.4mg/kg）不会导致纹状体中（+）[11C]DTBZ 结合增加，而是略有 5%的下降。我们的数据表明，低剂量安非他命不太可能导致足够的 DA 耗竭来检测增加的（+）[11C]DTBZ 结合，可能需要更高的剂量。
