DNA DAMAGE DETERMINATION BY THE ALKALINE ELUTION TECHNIQUE IN THE HEMOLYMPH OF MUSSEL MYTILUS-GALLOPROVINCIALIS TREATED WITH BENZO[A]PYRENE AND 4-NITROQUINOLINE-N-OXIDE

The ability of benzo[a]pyrene (BaP) and 4-nitroquinoline-N-oxide (NQO) to induce DNA breakage in haemolymph of mussel Mytilus galloprovincialis was studied using an alkaline elution assay. The elution of haemolymph DNA from control animals increased from pH 12.1-12.8 suggesting that DNA alkali-labile sites are already present in the haemolymph. The difference between control and treated ones is sufficient at pH 12.3 that additional alkali-labile sites and single-strand breaks caused by BaP and NQO can be measured. Elution of haemolymph DNA, from both BaP and NQO treated mussels, was found to increase in a dose-dependent manner after 1.5 h, followed by decrease in the elution rate depending on dose, after 48 h for BaP and 5 days for NQO. The results indicate that repair of DNA in mussel haemolymph is significant and dependent on the dose of chemical applied. DNA damage in BaP treated mussels could be explained by formation of peroxides and/or radicals during low BaP metabolism, and their effects on DNA. © 1990.