title: The effect of peroral administration of toxic cyanobacteria on laboratory rats (Rattus norvegicus var. alba).
abstract: OBJECTIVE
  The toxic cyanobacteria are a serious problem for water supply systems, recreation, and agriculture. Cyanobacteria produce numerous bioactive compounds including microcystins - the most studied cyanobacterial hepatotoxins. Only rare studies addressed realistic situation, i.e. impact of MCs accumulated in the fish tissues on the overall physiology. The aim of the present study was to provide a model simulation of the simple food chain for evaluation of impacts of cyanobacteria on the rat physiology under different exposure scenario.
  
  
  METHODS
  Experimental rats were fed with food with fish meat, which contained external additions of isolated microcystins as well as toxic cyanobacteria Microcystis, nontoxic cyanobacteria Arthrospira and green alga Chlorella. Subgroups of the animals were also challenged with a model antigen KLH to investigated immune-related parameters. We studied parameters of oxidative stress in the liver as levels of lipid peroxidation and glutathion levels. Series of hematological, biochemical and immunological parameters were also investigated.
  
  
  RESULTS
  Although considerable amounts of microcystins were administered to rats, all levels of MCs were under the detection limit (1 ng/g fresh weight) in the rat tissues using tandem LC/MS. Only some conjugates of microcystins with cystein and glutathion were detected in the rat liver exposed to Microcystis biomass (values were around the detection limit). Statistically significant depletion of body and liver weight was observed in groups with microcystin addition in comparison with all other groups. Rats exposed to MCs had stimulated immune system (showed higher antibody answer on administered antigen). Also modulation of some lymphocyte subpopulations was recorded with the most interesting observation of stimulated NK cell numbers in groups exposed to isolated toxins (but not to biomass containing the same toxin amount).
  
  
  CONCLUSIONS
  Our study demonstrates that oral exposure to microcystins in the diet may induce some detoxification responses and modulation of some hematological and immunological parameters.
authors.affiliation: Research Centre for Toxic Compounds in the Environment (RECETOX), Masaryk University - Faculty of Science Brno, Czech Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Adamovsky
authors.forename: Radovan
authors.initials: R
authors.lastname: Kopp
authors.forename: Andrea
authors.initials: A
authors.lastname: Zikova
authors.forename: Ludek
authors.initials: L
authors.lastname: Blaha
authors.forename: Jiri
authors.initials: J
authors.lastname: Kohoutek
authors.forename: Petra
authors.initials: P
authors.lastname: Ondrackova
authors.forename: Hana
authors.initials: H
authors.lastname: Paskerova
authors.forename: Jan
authors.initials: J
authors.lastname: Mares
authors.forename: Miloslava
authors.initials: M
authors.lastname: Palikova
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000830:Animals, Laboratory; D001427:Bacterial Toxins / Q000494:pharmacology / Q000633:toxicity*; D000458:Cyanobacteria / Q000472:pathogenicity / Q000502:physiology*; D000087522:Cyanobacteria Toxins; D004435:Eating / Q000502:physiology*; D005396:Fish Products / Q000633:toxicity; D005506:Food Contamination; D005978:Glutathione / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008387:Marine Toxins / Q000494:pharmacology / Q000633:toxicity*; D052998:Microcystins / Q000494:pharmacology / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D008387:Marine Toxins; D052998:Microcystins; C078588:microcystin; D005978:Glutathione