BIOACCUMULATION OF CYANOTOXINS IN BRAZILIAN MOLLUSKS

PY-DANIEL K. R.(1), VIZZOTTO C. S. (1), SCHWARTZ  C. A. (1), MELO J. A. T. (2), BLOCH JR C.(2), PIRES JR O.R.(1)

(1) Laboratório de Toxinologia, Departamento de Ciências Fisiológicas, IB-UnB; (2) Laboratório de Espectrometria de Massa, EMBRAPA-CENARGEN.

Cyanotoxins produced by freshwater cyanobacteria are very common worldwide, and have been reported to cause poisonings and deaths of wild and domestic animals even significant hazards to human health. In this study we examined the presence of Microcystins and Saxitoxins in two mollusks, Pomacea lineata (Gastropoda) and Corbicula fluminae (Bivalvia). The mollusks were collected in Paranoá Lake, Brasília, Brazil and brought to Laboratório de Toxinologia-UnB, where they were extracted and semipurified for further analysis.  For microcystins, the toxins was identified by UV spectrogram in HPLC-PDA/UV system and MS spectral data. And for Saxitoxins a HPLC system accomplished with a fluorescence post-column reaction and MS spectral data. Pomacea lineata extracts present 3 types of Microcystins (MC-LR, MC-RR and DleuMC-LR) and a unknown saxitoxin derivative, and Corbicula fluminae extract presents GTX1 and GTX5, both saxitoxins derivatives, suggesting that both mollusks are good bioindicators for cyanotoxins. These preliminaries results are from a 1 year project for monitoring the dynamics of microcystins and saxitoxins in aquatic animals of Paranoá Lake.

FINANCIAL SUPPORT: CNPq.

CORRESPONDENCE TO:OSMINDO RODRIGUES PIRES JÚNIOR, Laboratório de Toxinologia, Instituto de Biologia, Universidade de Brasília. Phone: 61 3307 2160. Fax:  61 3274 1251. Email: osmindo@unb.br