Choi H O, Hwang K J
J Nucl Med. 1987 Jan;28(1):91-6.
The use of mobile ionophores to facilitate the transport of 111In through a lipid bilayer membrane has broad applications in liposome technology and cell labeling. However, the mechanism of such ionophore-mediated transport of 111In through a lipid bilayer membrane is not completely clear. The present report describes the correlations of the behaviors of ionophoric loading of 111In into liposomes with the lipophilicity and the indium-binding affinity of three ionophores, namely, 8-hydroxyquinoline, acetylacetone, and tropolone. Our results suggest that the mechanism of the ionophoric transport of 111In through a lipid bilayer membrane involves the rapid exchange of 111In cations among the ionophores in both the aqueous solution and the lipid bilayer. Furthermore, the effectiveness of an ionophore in facilitating the transport of 111In from the external aqueous compartment to the entrapped nitrilotriacetic acid depends not only on the lipophilicity of the [111In]ionophore complex, but also on the lipophilicity of the free ionophore itself and the competition of 111In between nitrilotriacetic acid inside the inner aqueous compartment of the liposome and the ionophore imbedded in the lipid bilayer membrane of the liposome.
使用移动离子载体促进¹¹¹铟通过脂质双分子层膜的运输在脂质体技术和细胞标记方面有广泛应用。然而，这种离子载体介导的¹¹¹铟通过脂质双分子层膜的运输机制尚不完全清楚。本报告描述了¹¹¹铟在脂质体中离子载体负载行为与三种离子载体（即8-羟基喹啉、乙酰丙酮和托酚酮）的亲脂性及铟结合亲和力之间的相关性。我们的结果表明，¹¹¹铟通过脂质双分子层膜的离子载体运输机制涉及¹¹¹铟阳离子在水溶液和脂质双分子层中的离子载体之间快速交换。此外，离子载体促进¹¹¹铟从外部水相区室运输到包封的次氮基三乙酸的有效性不仅取决于[¹¹¹铟]离子载体络合物的亲脂性，还取决于游离离子载体本身的亲脂性以及脂质体内水相区室中的次氮基三乙酸与脂质体脂质双分子层中嵌入的离子载体之间对¹¹¹铟的竞争。
