Moerlein S M, Daugherty A, Sobel B E, Welch M J
Department of Biochemistry and Molecular Biophysics, Mallinckrodt Institute of Radiology, Washington University Medical School, St. Louis, MO 63110.
J Nucl Med. 1991 Feb;32(2):300-7.
Low-density lipoprotein (LDL) labeled with either gallium-68 (68Ga) or indium-111 (111In) was evaluated as a potential PET or SPECT radiopharmaceutical for determination of hepatic lipoprotein metabolism in rabbits. Gallium-68 or 111In was linked to LDL via diethylenetriaminepentaacetic acid (DTPA) with a 25-70% radiochemical yield. Studies in vivo that compared 68Ga- or 111In-DTPA-LDL with dilactitol-[125I]-tyramine LDL and 131I-LDL showed that both 68Ga- and 111In-labeled LDL behaved as residualizing radiotracers. Localization of radioactivity within the liver of normal rabbits was visualized clearly with [68Ga]DTPA-LDL by PET and with [111In]DTPA-LDL by gamma scintigraphy. Significant differences were observed in hepatic uptake of normal compared with hypercholesterolemic rabbits in which low-capacity LDL receptor-mediated catabolism was saturated. Gallium-68 and 111In-DTPA-LDL are attractive radiopharmaceuticals for noninvasive delineation of tissue LDL metabolism under normal and pathophysiologic conditions.
用镓 - 68（68Ga）或铟 - 111（111In）标记的低密度脂蛋白（LDL）被评估为一种潜在的正电子发射断层扫描（PET）或单光子发射计算机断层扫描（SPECT）放射性药物，用于测定兔肝脏脂蛋白代谢。镓 - 68或铟 - 111通过二乙烯三胺五乙酸（DTPA）与LDL相连，放射化学产率为25 - 70%。体内研究比较了68Ga - DTPA - LDL或111In - DTPA - LDL与二乳糖醇 - [125I] - 酪胺LDL和131I - LDL，结果表明68Ga和111In标记的LDL均表现为残留放射性示踪剂。通过PET用[68Ga]DTPA - LDL和通过γ闪烁显像用[111In]DTPA - LDL可清晰观察到正常兔肝脏内的放射性定位。在低容量LDL受体介导的分解代谢饱和的高胆固醇血症兔与正常兔之间，观察到肝脏摄取存在显著差异。镓 - 68和111In - DTPA - LDL是用于在正常和病理生理条件下无创描绘组织LDL代谢的有吸引力的放射性药物。
