Rahimian J, Glass E C, Touya J J, Akber S F, Graham L S, Bennett L R
J Nucl Med. 1984 Jan;25(1):31-7.
Selective pulmonary uptake of many natural and synthetic substances has been demonstrated by physiologists and pharmacologists using isolated perfused lung preparations or invasive techniques. It is difficult, however, to relate these laboratory studies to disease processes and to the study of problems encountered in a clinical environment. Our goal was to develop a noninvasive method for studying the pulmonary uptake of tracer substances using available radiotracers, gamma cameras, and computers that would give information similar, if not identical, to that from the invasive laboratory methods, and that could be applied in a clinical setting. The multiple-indicator dilution technique, modified for external counting, is well suited for such studies of pulmonary uptake of tracer substances. In this study, Tc-99m micro sulfur colloid (Tc-99m micro SC) was used as an intravascular reference tracer, N-isopropyl-p-[123I]iodoamphetamine (I-123 IMP) as a cellular test tracer amine, and In-111 DTPA as an extracellular tracer. Calculated first-pass lung uptakes of I-123 IMP and In-111 DTPA were 0.92 +/- 0.04 and 0.17 +/- 0.04, respectively, relative to the reference tracer. Using this approach, the first-pass pulmonary extraction of a variety of radiolabeled test tracers can be measured in a clinical environment in a variety of physiologic settings.
生理学家和药理学家利用离体灌注肺标本或侵入性技术已证实，许多天然和合成物质可被肺选择性摄取。然而，很难将这些实验室研究与疾病过程以及临床环境中遇到的问题研究联系起来。我们的目标是开发一种非侵入性方法，利用现有的放射性示踪剂、γ相机和计算机来研究示踪物质的肺摄取情况，该方法能提供与侵入性实验室方法相似（即便不完全相同）的信息，且可应用于临床环境。为进行体外计数而改良的多指示剂稀释技术非常适合此类示踪物质肺摄取的研究。在本研究中，锝-99m微硫胶体（Tc-99m微SC）用作血管内参考示踪剂，N-异丙基-p-[123I]碘安非他明（I-123 IMP）用作细胞测试示踪胺，铟-111二乙三胺五乙酸（In-111 DTPA）用作细胞外示踪剂。相对于参考示踪剂，I-123 IMP和In-111 DTPA的计算首次通过肺摄取率分别为0.92±0.04和0.17±0.04。采用这种方法，可在临床环境中的各种生理状态下测量多种放射性标记测试示踪剂的首次通过肺摄取率。
