title: Alterations in neurobehaviors and inflammation in hippocampus of rats induced by oral administration of microcystin-LR.
abstract: Microcystin-LR (MC-LR) is a widely studied toxic peptide secreted by certain water blooms of cyanobacteria that exhibit hepatotoxicity and neural toxicity. This study aimed to observe the neurotoxic effects of low-dose MC-LR exposure by oral administration. Male Sprague-Dawley (SD) rats were administered orally every 2 days for 8 weeks with pure water and 0.2, 1.0, and 5.0 μg/kg MC-LR. The Morris water maze test was used to assess the spatial learning and memory capability of rats. The activation of astrocytes and nitric oxide synthase (NOS) was evaluated by immunohistochemistry, and concentrations of nitric oxide (NO) in rat hippocampus were analyzed. Slight liver dysfunction was observed in the 5.0 μg/kg MC-LR-treated rats. Impairment of spatial learning and memory was also observed in the 5.0 μg/kg MC-LR-treated rats. Astrocytes in the hippocampus of the 5.0 μg/kg MC-LR-treated rats showed enhanced activation and cell density; the inflammatory indicators, NOS and NO, increased in accordance with astrocyte activation. This study showed that oral exposure of MC-LR had adverse affects on neurobehaviors, and induced inflammation in memory-related brain regions.
authors.affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Dingjiaqiao 87, Nanjing, 210009, China, Lixiaobo1007@hotmail.com.
authors.forename: Xiao-Bo
authors.initials: XB
authors.lastname: Li
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Jingjuan
authors.initials: J
authors.lastname: Ju
authors.forename: Yunhui
authors.initials: Y
authors.lastname: Li
authors.forename: Lihong
authors.initials: L
authors.lastname: Yin
authors.forename: Yuepu
authors.initials: Y
authors.lastname: Pu
mesh_terms: D000284:Administration, Oral; D000704:Analysis of Variance; D000818:Animals; D001253:Astrocytes / Q000187:drug effects; D000458:Cyanobacteria / Q000737:chemistry*; D004789:Enzyme Activation / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects*; D007150:Immunohistochemistry; D007249:Inflammation / Q000139:chemically induced*; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008297:Male; D008387:Marine Toxins; D018782:Maze Learning / Q000187:drug effects*; D052998:Microcystins / Q000008:administration & dosage / Q000633:toxicity*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D008387:Marine Toxins; D052998:Microcystins; D019001:Nitric Oxide Synthase; C057862:cyanoginosin LR