title: Lateral diffusion of manganese in the rat brain determined by T(1) relaxation time measured by (1)H MRI.
abstract: In order to optimize manganese ion-enhanced MRI in thalamic and hypothalamic nuclei, we analyzed the diffusion of manganese in the brain followed by the intra-cerebroventricular application of manganese-bicine (Mn-bicine). T(1)-weighted MRI intensities, with 9-pixel ROIs in the hypothalamus perpendicular to the third ventricle, were measured during continuous infusion of Mn-bicine solution in the lateral cerebroventricle. Using a relationship between the image intensity of T(1)-weighted MRI and T(1) relaxation time, the image intensity was converted into the concentration of manganese. Assuming a simple diffusion process, the apparent diffusion coefficient (D (ap)) of manganese (4.2 × 10(-5) mm(2) s(-1)) is much lower than that of water (6 × 10(-4) mm(2) s(-1)), and the D (ap) tended to decrease when the distance from the third ventricle increased. These results suggest (1) the Mn(2+) ion is trapped by neural cells during diffusion and (2) the manganese efflux is discharged from the brain via veins.
authors: Department of Regulatory Physiology, Dokkyo Medical University School of Medicine, Tochigi, Japan. yseo@dokkyomed.ac.jp
authors: Yoshiteru
authors: Y
authors: Seo
authors: Akira
authors: A
authors: Takamata
authors: Takashi
authors: T
authors: Ogino
authors: Hironobu
authors: H
authors: Morita
authors: Masataka
authors: M
authors: Murakami
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D002552:Cerebral Ventricles / Q000378:metabolism; D004058:Diffusion; D007026:Hypothalamic Area, Lateral / Q000378:metabolism; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008345:Manganese / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D013787:Thalamic Nuclei / Q000378:metabolism
chemical_list: D008345:Manganese