Noninvasive topical loading for manganese-enhanced MRI of the mouse visual system.
Noninvasive topical loading for manganese-enhanced MRI of the mouse visual system.
复制标题
DOI：
10.1167/iovs.10-6363
复制
发表时间：
2011-05
影响因子：
4.4
通讯作者：
Shu-wei Sun;Bruce Campbell;C. Lunderville;Eric Won;Hsiao-Fang Liang
中科院分区：
文献类型：
--
作者：
Shu-wei Sun;Bruce Campbell;C. Lunderville;Eric Won;Hsiao-Fang Liang
目的评价局部载药作为玻璃体内注射Mn（2+）增强磁共振成像（MEMRI）视觉系统的替代方法。方法用0.5 ~ 1.5M MnCl（2）局部注射和0.5 μL 100 mM和2 μL 1 M MnCl（2）玻璃体腔注射，观察小鼠MEMRI的免疫组化。在另一组小鼠中，两次局部给予1 M Mn（2+），间隔7天应用于相同的动物，以评估MEMRI在时程研究中的使用。还进行了动态成像以揭示Mn（2+）如何行进到视网膜。还在视网膜缺血的眼睛中进行了局部负载MnCl（2）的MEMRI，以评估增强是否需要健康的神经元。结果1d后，局部注射1 M和1.5 M MnCl（2）可使上级丘的信号显著增强（达20%）（P < 0.05），与2 μL 1 M注射液的增强效果相当。重复暴露于Mn（2+）显示再现增强。动态影像显示虹膜、视网膜和透镜边界明显增强，但玻璃体腔无明显增强。在视网膜缺血眼中，视神经中未检测到MEMRI增强。Mn（2+）局部给药1周后，视神经（视交叉前1.5 mm）和视网膜的免疫组织化学显示无损伤。结论：局部应用Mn（2+）治疗MEMRI是可行的。局部负载的Mn（2+）没有扩散到玻璃体空间中，但它可能已被吸收到虹膜中以扩散或通过毛细血管循环到达视网膜。
PURPOSE To evaluate topical loading as an alternative to intravitreal injection for Mn(2+)-enhanced magnetic resonance imaging (MEMRI) of the visual system. METHODS Topical administration of 0.5 to 1.5 M MnCl(2) and intravitreal injections with 0.5 μL 100 mM and 2 μL 1 M MnCl(2) for mouse MEMRI were conducted, followed by immunohistochemistry. In another mouse group, two topical administrations of 1 M Mn(2+) were applied to the same animals 7 days apart, to evaluate the use of MEMRI in a time course study. Dynamic imaging was also conducted to reveal how Mn(2+) travels to the retina. MEMRI with topically loaded MnCl(2) was also conducted in eyes with retinal ischemia, to evaluate whether the enhancements required healthy neurons. RESULTS After 1 day, topical administration of 1 M and 1.5 M MnCl(2) rendered significant signal enhancement (up to 20%) in the superior colliculus (P < 0.05) that was equivalent to that of the 2-μL 1 M injection. Repeated exposure to Mn(2+) showed reproduced enhancement. Dynamic imaging showed significant enhancement in the iris, retina, and lens boundary, but not in the vitreous space. In retinal ischemic eyes, no enhancement of MEMRI was detected in the optic nerves. The immunohistochemistry of the optic nerve (1.5 mm anterior to the chiasm) and retina showed no injury 1 week after Mn(2+) topical administrations to each mouse. CONCLUSIONS The results demonstrated the feasibility of using topical administration of Mn(2+) for MEMRI. Topically loaded Mn(2+) did not diffuse into the vitreous space, but was it may have been absorbed into the iris to diffuse or travel via the capillary circulation to reach the retina.