INTERACTION OF MRI GD CONTRAST AGENTS W/ MEMBRANES AS STUDIED BY HF EPR

两种MRI钆造影剂的相互作用，钆 乙氧基苄基-二亚乙基三胺五乙酸酯（Gd-EOB-DTPA）和 钆2-戊基-（1，4，7，10-四氮杂环十二烷-N，N '，N "， N ""-四乙酸）（Gd-DOTA-P），与多层磷脂 分散体，其制备自 1，2-二棕榈酰-sn-甘油-3-磷脂酰胆碱（DPPC）已被 在95 GHz的高分辨率EPR光谱研究。 在 3.3T EPR谱的共振场， 2，2，6，6-四甲基-1-哌啶基氧基（克里思），分配在 水相和膜相清晰地分离， 测头的动力学参数的准确性和明确性。 结果 显示尽管存在更亲脂的造影剂， Gd-DOTA-P，可以在双层内检测到， 膜的组织即使在 生理高浓度（5mM）。 的温度 双层的主要相变也不受影响， 在0.4oC的测定精度范围内。

Interactions of two MRI gadolinium contrast agents, gadolinium ethoxybenzyl-diethylenetriaminepentaacetate (Gd-EOB-DTPA) and gadolinium 2-pentyl-(1,4,7,10-tetraazacyclododecane-N, N', N'', N'''-tetraacetic acid) (Gd-DOTA-P), with multibilayer phospholipid dispersions prepared from 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) have been investigated with high resolution EPR spectroscopy at 95 GHz. At a resonance field of 3.3 T EPR spectra of a small nitroxide probe, 2,2,6,6-tetramethyl-1-piperidinyloxy (Tempo), partitioned between aqueous and membrane phases are clearly resolved, making measurements of dynamics parameters of the probe accurate and unambiguous. Results show that although the presence of the more lipophilic contrast agent, Gd-DOTA-P, can be detected within the bilayer, the structural organization of the membrane remains unaffected even at physiologically high (5mM) concentrations. The temperature of the main phase transition of the bilayer was also unaffected to within the 0.4oC accuracy of its determination.