LYSOSOMAL REACTION TO XENOBIOTICS IN MUSSEL HEMOCYTES USING BODIPY-FL-VERAPAMIL

Many cellular and sub-cellular biomarkers associated with mussel (Myti lus edulis) digestive gland and kidney have been characterised. The ly sosomal compartment of these tissues have been recognised as being par ticularly sensitive, exhibiting pollutant induced responses which coul d be potentially used as a 'biomarker'. However, relatively few studie s have investigated the lysosomal response within molluscan hemocytes. This study was conducted to test whether lysosomal reactions, in live hemocytes isolated from mussels, can be used as a biomarker of pollut ant exposure and deleterious effect. Lysosomal responses to a number o f hydrocarbons, including anthracene and phenanthrene, and to the amph iphilic heterocylic chemical, chlorpromazine, were examined. The supra vital dye neutral red (NR) was used to examine lysosomal membrane frag ility, following xenobiotic exposure. NR was also used to verify the l ysosomal compartment as the reported accumulation site of a new molecu lar probe, BODIPY-FL-verapamil (BFLV). The use of BFLV, with confocal laser microscopy and image analysis enabled visualisation and quantifi cation of lysosomal distribution and perturbation. BFLV showed that ex posure of molluscan hemocytes to xenobiotics (20 ppb-10 ppm) induced t he formation of pathologically enlarged lysosomes. The internal traffi cking of lysosomes was shown to be severely compromised after exposure to chlorpromazine. Exposed molluscan hemocytes exhibited significantl y reduced lysosomal retention times, for neutral red. Preliminary data is presented demonstrating the opportunity for these non-destructive biomarker techniques to detect pollution gradients in situ. Crown copy right (C) 1996 Published by Elsevier Science Ltd