[The observation of blood-brain barrier of organic mercury poisoned rat: a Gd-DTPA enhanced magnetic resonance study].

Permeability of the blood-brain barrier (BBB) of methylmercury chloride (MMC) intoxicated rat brain was studied in vivo by gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) enhanced magnetic resonance imaging (MRI), measuring the longitudinal relaxation time (T1) and the transverse relaxation time (T2). MMC intoxicated rat brain showed the prolonged T1 in the cerebral white matter and prolonged T2 in the cerebellar cortex. After Gd-DTPA administration, T1 of cerebral and cerebellar white matter shortened from 1.647 to 1.344 sec., and 1.290 to 1.223 sec. respectively. On the contrary, T2 showed no change after Gd-DTPA injection. It was concluded that, although the shortening of T1 after Gd-DTPA enhancement was rather little when compared with experimental brain ischemia, the shortening of the relaxation time of the MMC intoxicated rat brain was caused by the increased permeability of BBB.