London R E, Toney G, Gabel S A, Funk A
National Institute of Environmental Health Sciences, NIH, Res. Triangle Park, NC 27709.
Brain Res Bull. 1989 Sep;23(3):229-35. doi: 10.1016/0361-9230(89)90152-4.
An understanding of the distribution of manganese ions in the brain is of interest in connection with the development of an understanding of the neurotoxicity of this element. Information about the time dependent biodistribution of manganese ions in the brains of intact rats subsequent to single IP injections of MnCl2 has been obtained from magnetic resonance imaging (MRI) studies. The enhanced MRI contrast is based on the reduction in the spin lattice relaxation time (T1) of water protons which exchange into the coordination sphere of the manganese ions. These studies indicate rapid and significant accumulations of water accessible manganese in the ventricles, the pineal gland, and the pituitary gland. The rapid appearance of high levels of manganese in the ventricular cerebrospinal fluid indicates that manganese readily crosses the filtration barrier of the choroid plexus and is thereafter apparently absorbed by the ependymal surfaces of the ventricles and transported to the subarachnoid space.
了解锰离子在大脑中的分布，对于深入认识该元素的神经毒性具有重要意义。通过磁共振成像（MRI）研究，已获取了完整大鼠单次腹腔注射氯化锰后，锰离子在大脑中的时间依赖性生物分布信息。MRI造影增强是基于与锰离子配位球交换的水质子自旋晶格弛豫时间（T1）的缩短。这些研究表明，脑室、松果体和垂体中可接触水的锰迅速且大量积累。脑室脑脊液中迅速出现高浓度的锰，表明锰很容易穿过脉络丛的滤过屏障，之后显然被脑室的室管膜表面吸收并转运至蛛网膜下腔。
