In vivo manganese-MR imaging of calcium influx in spontaneous rat pituitary adenoma
In vivo manganese-MR imaging of calcium influx in spontaneous rat pituitary adenoma
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DOI：
10.3174/ajnr.a0693
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发表时间：
2007-11-01
影响因子：
3.5
通讯作者：
Minoshima, S.
中科院分区：
文献类型：
--
作者：
Cross, D. J.;Flexman, J. A.;Minoshima, S.
背景和目的：在老年大鼠的MR成像过程中，钙类似物锰（Mn 2+）快速摄取到自发性垂体腺瘤中产生了一种假设，即神经内分泌肿瘤可能具有触发激素释放所需的相应钙内流增加。本研究的目的是探讨磁共振成像结合M2+（Mn-MR成像）的垂体腺瘤的临床评价的潜力。材料和方法：Mn-MR成像的特点在正常老年大鼠垂体以及自发性垂体腺瘤的动态钙内流。为了证实Mn ~（2+）作为钙类似物的有效性，我们用钙通道阻滞剂维拉帕米抑制正常大鼠嗅球和垂体对Mn ~（2+）的摄取。患有腺瘤的大鼠接受氟脱氧葡萄糖正电子发射断层扫描（FDG-PET）以表征肿瘤代谢。Mn 2+内流的特点是在培养的垂体腺瘤cells.RESULTS：体积感兴趣的分析，正常老年垂体腺瘤与腺瘤显示更快，增加的钙内流在1，3，11，48小时。正常大鼠嗅球和垂体对Mn ~（2+）的摄取可被钙通道阻滞剂抑制，并在动态磁共振成像上表现出剂量依赖性抑制。FDG-PET显示肿瘤能量代谢和Mn 2+流入以及肿瘤大小之间的相关性。结论：这些结果表明，腺瘤有增加的活性依赖性钙离子流入与正常老年人垂体相比，这表明开发锰磁共振成像的垂体和其他神经内分泌肿瘤的临床工作的潜力为人类。
BACKGROUND AND PURPOSE: Rapid uptake of the calcium analog manganese (Mn2+) into spontaneous pituitary adenoma during MR imaging of aged rats generated the hypothesis that neuroendocrine tumors may have a corresponding increase in calcium influx required to trigger hormonal release. A goal of this study was to investigate the potential for clinical evaluation of pituitary adenoma by MR imaging combined with administration of M2+ (Mn-MR imaging).MATERIALS AND METHODS: Mn-MR imaging was used to characterize the dynamic calcium influx in normal aged rat pituitary gland as well as spontaneous pituitary adenoma. To confirm the validity of Mn2+ as a calcium analog, we inhibited Mn2+ uptake into the olfactory bulb and pituitary gland of normal rats by using the calcium channel blocker verapamil. Rats with adenomas received fluorode-oxyglucose-positron-emission tomography (FDG-PET) scanning for characterization of tumor metabolism. Mn2+ influx was characterized in cultured pituitary adenoma cells.RESULTS: Volume of interest analysis of the normal aged pituitary gland versus adenoma indicated faster and increased calcium influx in adenoma at 1, 3, 11, and 48 hours. Mn2+ uptake into the olfactory bulb and pituitary gland of normal rats was inhibited by calcium channel blockers and showed dose-dependent inhibition on dynamic MR imaging. FDG-PET indicated correlation between tumor energy metabolism and Mn2+ influx as well as tumor size.CONCLUSION: These results indicate that adenomas have increased activity-dependent calcium influx compared with normal aged pituitary glands, suggesting a potential for exploitation in the clinical work-up of pituitary and other neuroendocrine tumors by developing Mn-MR imaging for humans.