Goldstein D S, Holmes C, Stuhlmuller J E, Lenders J W, Kopin I J
Clinical Neuroscience Branch, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland 20892-1424, USA.
Clin Auton Res. 1997 Feb;7(1):17-29. doi: 10.1007/BF02267622.
Thoracic positron emission tomographic (PET) scanning after injection of 6-[18F]fluorodopamine ([18F]-6F-DA) visualizes cardiac sympathetic innervation. We tested whether changes in curves relating myocardial [18F]-6F-DA-derived radioactivity with time (time-activity curves, TACs) can reflect changes in important aspects of cardiac sympathetic function. Thoracic PET scans were obtained after intravenous administration of [18F]-6F-DA or the perfusion imaging agent [13N]ammonia into normal volunteers. Ganglion blockade with trimethaphan (TRI) was used to decrease sympathoneural traffic, desipramine (DMI) to block neuronal uptake of catecholamines, and tyramine (TYR) to displace vesicular amines. After [18F]-6F-DA administration, myocardial concentrations of [18F]-6F-DA-derived radioactivity declined bi-exponentially from the peak value. TRI increased the y-intercept (yo) value for the early phase (p = 0.01), and DMI decreased the yo for the late phase (p = 0.01). The TRI effect did not result from increased arterial [18F]-6F-DA concentrations or from increased myocardial perfusion. TYR infusion, begun 90 min after [18F]-6F-DA administration, accelerated the decline of myocardial radioactivity by 2.6-fold (p = 0.003). Alterations in post-ganglionic sympathoneural traffic, neuronal catecholamine uptake, and vesicular turnover of monoamines produce distinct changes in myocardial TACs after [18F]-6F-DA injection. [18F]-6F-DA PET scanning may therefore enable assessments of effects of stressors, drugs, and neurocardiological disorders on specific aspects of cardiac sympathoneural function.
注射6-[18F]氟多巴胺（[18F]-6F-DA）后进行胸部正电子发射断层扫描（PET）可显示心脏交感神经支配情况。我们测试了心肌[18F]-6F-DA衍生放射性随时间变化的曲线（时间-活性曲线，TACs）的变化是否能反映心脏交感神经功能重要方面的变化。在向正常志愿者静脉注射[18F]-6F-DA或灌注显像剂[13N]氨后进行胸部PET扫描。使用三甲噻芬（TRI）进行神经节阻滞以减少交感神经冲动传递，使用地昔帕明（DMI）阻断神经元对儿茶酚胺的摄取，并使用酪胺（TYR）置换囊泡胺。注射[18F]-6F-DA后，心肌中[18F]-6F-DA衍生放射性的浓度从峰值呈双指数下降。TRI增加了早期的y轴截距（yo）值（p = 0.01），而DMI降低了晚期的yo值（p = 0.01）。TRI的作用并非源于动脉[18F]-6F-DA浓度的增加或心肌灌注的增加。在注射[18F]-6F-DA 90分钟后开始输注TYR，使心肌放射性的下降加速了2.6倍（p = 0.003）。节后交感神经冲动传递、神经元儿茶酚胺摄取和单胺囊泡周转的改变在注射[18F]-6F-DA后会使心肌TACs产生明显变化。因此，[18F]-6F-DA PET扫描可能有助于评估应激源、药物和神经心脏病学疾病对心脏交感神经功能特定方面的影响。
