Use of freshly prepared rat hepatocytes to study toxicity of blooms of the blue‐green algaeMicrocystis aeruginosaandOscillatoria agardhii

Abstract

Extracts from blue-green algal blooms (Microcystis aeruginosa and Oscillatoria agardhii) from different lakes in southeastern Norway were tested for toxicity toward freshly prepared rat hepatocytes. The toxicity effects were scored by means of morphological studies of the cells and by measuring leakage of the enzyme lactate dehydrogenase (LDH) from the cells. The results with the hepatocytes correspond well with results from the traditional mouse bioassay, concerning both ability to distinguish between toxic and nontoxic samples and estimation of relative toxicity. Morphological changes due to toxic effects on the plasma membrane appeared earlier than leakage of enzyme from damaged cells. The results indicate that the hepatocyte-toxicity assay system might be well suited for screening purposes concerning water contamination by blue-green algae.

A comparison of in vivo and in vitro assays to assess the toxicity of algal blooms

“…The different EC 50 values obtained with the catfish primary hepatocytes and rat primary hepatocytes could be due to the differences in exposure times of these primary hepatocytes to the cyanotoxins. Other investigators have demonstrated the successful use of mammalian and rainbow trout primary hepatocytes in determining cytotoxicity of the cyanotoxins (Aune and Berg, 1986;Heinze, 1996;Boaru et al, 2006). Because of their sensitivity and their ability to function similar to the liver in vivo, isolated primary hepatocytes provide an attractive alternative to the mouse assay in toxicity testing of cyanotoxins.…”

“…The disadvantage of the mouse test is that it does not have the sensitivity or precision required to be applicable to water samples with concentrations around 1-2 mg/l, the approximate range of the guideline for microcystin-LR (MC-LR) prescribed by the World Health Organization (WHO) (WHO, 1998). For ethical reasons, the mouse test is unsuitable for large scale and routine testing of field samples (Aune and Berg, 1986;Heinze, 1996). In recent years, in vitro toxicity tests involving the use of cultured cells have been developed to provide a substitute for the mouse bioassay (Storey et al, 1983;Aune and Berg, 1986;Berg and Aune, 1987;Heinze, 1996).…”

“…For ethical reasons, the mouse test is unsuitable for large scale and routine testing of field samples (Aune and Berg, 1986;Heinze, 1996). In recent years, in vitro toxicity tests involving the use of cultured cells have been developed to provide a substitute for the mouse bioassay (Storey et al, 1983;Aune and Berg, 1986;Berg and Aune, 1987;Heinze, 1996). The major advantage of using freshly isolated hepatocytes is their ability to maintain the activities of phase I and II drug-metabolizing enzymes, thus allowing various investigations to be performed including determination of metabolic profiles, inhibition and induction effects (Fautrel et al, 1991;Guillouzo, 1998).…”

“…Toxicity of purified MC-LR (Sigma-Aldrich, Gauteng, South Africa) and cyanobacterial extracts were tested using the mouse bioassay according to the method described by Aune and Berg (1986). One millilitre of MC-LR concentrations (0.001, 0.005, 0.01, 0.025, 0.05, 0.1, 3.125, 6.25, 12.5, 25 and 50 mg/l) was injected intraperitoneally (i.p.)…”

Management of toxic blue-green algae (cyanobacteria) in Australia

“…Other techniques which have been used to detect the activity of microcystins include the use of Ž . isolated rat hepatocytes Aune and Berg, 1986 , brine Ž shrimp Kiviranta et al, 1991;Campbell et al, 1994; . Ž Lahti et al, 1995 , and hamster lung fibroblasts Codd .…”