title: Reduction of manganese intake improves neuropsychological manifestations in rats with minimal hepatic encephalopathy.
abstract: Brain manganese deposition is led by liver dysfunction and/or portal-systemic shunting in minimal hepatic encephalopathy (MHE). Manganese is toxic and can cause cognitive disorders and extrapyramidal symptoms. Thus, reduction of manganese intake might be considered as a potential treatment strategy for MHE. In this study we aimed to investigate whether low- or no-manganese feed can improve the neuropsychological manifestations in MHE rats. Rats with MHE were established by partially ligating the portal vein and fed a manganese diet (MHE-M, 10mg per kg feed; n=24), a no-manganese diet (MHE-N; n=24) and a half-manganese diet (MHE-H; n=24) for 2, 4, 6 and 8weeks, with six rats in each subgroup. Morris water maze (MWM), open-field test and narrow beam test (NBT) were used to evaluate the cognitive and locomotor situations. Fasted blood ammonia, manganese content and glutamine synthetase (GS) activity in basal ganglia and cortex were measured. A significantly longer MWM escape latency, less locomotor activity, longer NBT latency and total time, higher blood ammonia, higher brain manganese content and GS activity were found in MHE-M rats. However, a significantly shorter MWM escape latency, increased locomotor activity, shorter NBT latency and total time, lower blood ammonia, lower brain manganese content and lower GS activity were found in MHE-N rats after no-manganese feed treatment. Partial improvements were found in MHE rats with half-manganese feed treatment. Reduction of manganese intake can significantly improve the cognitive and locomotor situations in MHE rats by reducing brain manganese content and regulating GS activity.
authors.affiliation: Department of Radiology, Jinshan Hospital, Fudan University, Shanghai 201508, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Dermatology, Jinshan Hospital, Fudan University, Shanghai 201508, China.
authors.forename: Li Hong
authors.initials: LH
authors.lastname: Mei
authors.affiliation: Department of Radiology, Jinshan Hospital, Fudan University, Shanghai 201508, China. Electronic address: dr.jinweiqiang@163.com.
authors.forename: Jin Wei
authors.initials: JW
authors.lastname: Qiang
authors.affiliation: Department of Radiology, Jinshan Hospital, Fudan University, Shanghai 201508, China.
authors.forename: Chang Xue
authors.initials: CX
authors.lastname: Ji
authors.affiliation: Department of Radiology, Jinshan Hospital, Fudan University, Shanghai 201508, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Ju
mesh_terms: D000641:Ammonia / Q000097:blood; D000818:Animals; D001921:Brain / Q000378:metabolism; D005243:Feces / Q000737:chemistry; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D006501:Hepatic Encephalopathy / Q000139:chemically induced / Q000378:metabolism* / Q000517:prevention & control / Q000523:psychology*; D008345:Manganese / Q000008:administration & dosage / Q000378:metabolism / Q000633:toxicity*; D018782:Maze Learning; D009043:Motor Activity; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D008345:Manganese; D000641:Ammonia; D005974:Glutamate-Ammonia Ligase
keywords: minimal hepatic encephalopathy; no-manganese diet; portal-systemic shunting