The toxicity of microcystin LR in mice following 7 days of inhalation exposure

Janet M. Benson, Julie A. Hutt, Kathleen Rein, Susan E. Boggs, Edward B. Barr, Lora E. Fleming

Research output: Contribution to journalArticle

26 Scopus citations

Abstract

Microcystins, a family of cyclic heptapeptides produced by the cyanobacteria, Microcystis aeruginosa, have documented hepatotoxic and tumor promoting activities. The purpose of this study was to evaluate the toxicity of inhaled microcystin LR (microcystin). Male BALB/c mice were exposed by nose-only inhalation to 260-265 μg microcystin/m3 for 7 days. The low-, mid- and high-dose groups were exposed for 0.5, 1, and 2 h, respectively. Control animals were sham exposed to aerosolized vehicle. Treatment-related microscopic lesions were observed only in the nasal cavity of the mid- and high-dose groups. These lesions consisted of minimal to moderate multifocal degeneration and necrosis of the respiratory epithelium, with variable neutrophilic inflammation and minimal to marked degeneration, necrosis, and atrophy of the olfactory epithelium. The no-adverse-effect dose for the nasal lesions was approximately 3 μg/kg body weight, or 20 ng/cm2 of nasal epithelium. In serum, only two protein peaks, occurring at m/zs of 11,688 and 11,829 Da, exhibited decreases in intensity that were microcystin dose-dependent. While these proteins have not been positively identified, they may be useful in the future as biomarkers of microcystin exposure in humans.

Original languageEnglish (US)
Pages (from-to)691-698
Number of pages8
JournalToxicon
Volume45
Issue number6
DOIs
StatePublished - May 2005

Keywords

  • Inhalation
  • Microcystin
  • Nasal epithelium
  • Protein expression in serum

ASJC Scopus subject areas

  • Toxicology

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    Benson, J. M., Hutt, J. A., Rein, K., Boggs, S. E., Barr, E. B., & Fleming, L. E. (2005). The toxicity of microcystin LR in mice following 7 days of inhalation exposure. Toxicon, 45(6), 691-698. https://doi.org/10.1016/j.toxicon.2005.01.004