Intracellular manganese ions provide strong T1 relaxation in rat myocardium
Intracellular manganese ions provide strong T1 relaxation in rat myocardium
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DOI：
10.1002/mrm.20199
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发表时间：
2004-09-01
影响因子：
3.3
通讯作者：
Jynge, P
中科院分区：
文献类型：
--
作者：
Nordhoy, W;Anthonsen, HW;Jynge, P
在大鼠心肌中评估锰离子（Mn 2+）作为细胞内（ic）造影剂的有效性。在从离体灌注心脏切下的心室组织中测量T-1和T-2以及Mn含量，其中用0、30、100、300或1000 μ M的Mn二吡哆二磷酸盐（MnDPDP）洗入5分钟，然后洗出15分钟以除去细胞外（ec）Mn 2+。在20 MHz下的反转恢复（IR）分析揭示了两个T-1分量：一个是和短的T1-1（650-251 ms），和一个ec和较长的T1-2（2712-1042 ms）。强度分别约为68%和32%。组织锰含量相关性特别好，是R1-1 A两个网站的水交换分析的T-1数据记录缓慢的水交换与是和EC的寿命分别为11.3秒和7.5秒，表观和内在的松弛参数之间没有差异。Mn ~（2+）在水中诱导的IC弛豫率高达56（s mM）（-1），分别是Mn ~（2+）水溶液和MnDPDP诱导的IC弛豫率的8倍和36倍。该值与迄今为止报道的任何合成蛋白质结合金属螯合物的值一样高。质子和电子（Mn 2+）自旋之间增加的旋转相关时间（τ（R））以及维持的内球水进入可能使得Mn 2+离子和Mn 2+离子释放造影剂对于T-1加权成像令人惊讶地有效。(C)2004 Wiley-Liss，Inc.
The efficacy of manganese ions (Mn2+) as intracellular (ic) contrast agents was assessed in rat myocardium. T-1 and T-2 and Mn content were measured in ventricular tissue excised from isolated perfused hearts in which a 5-min wash-in with 0, 30, 100, 300, or 1000 muM of Mn dipyridoxyl diphosphate (MnDPDP) was followed by a 15-min wash-out to remove extracellular (ec) Mn2+. An inversion recovery (IR) analysis at 20 MHz revealed two T-1 components: an is and short T1-1 (650-251 ms), and an ec and longer T1-2 (2712-1042 ms). Intensities were about 68% and 32%, respectively. Tissue Mn content correlated particularly well with is R1-1 A two-site water-exchange analysis of T-1 data documented slow water exchange with is and ec lifetimes of 11.3 s and 7.5 s, respectively, and no differences between apparent and intrinsic relaxation parameters. Ic relaxivity induced by Mn2+ ions in is water was as high as 56 (s mM)(-1), about 8 times and 36 times higher than with Mn2+ aqua ions and MnDPDP, respectively, in vitro. This value is as high as any reported to date for any synthetic protein-bound metal chelate. The increased rotational correlation time (tau(R)) between proton and electron (Mn2+) spins, and maintained inner-sphere water access, might make is Mn2+ ions and Mn2+-ion-releasing contrast media surprisingly effective for T-1-weighted imaging. (C) 2004 Wiley-Liss, Inc.