LYSOSOMAL MEMBRANE RESPONSES IN THE BLOOD AND DIGESTIVE CELLS OF MUSSELS EXPERIMENTALLY EXPOSED TO FLUORANTHENE

In order to determine if cellular responses to contaminant exposure differed between cell types, from within the same host, neutral red retention (NRR) was used as a determinant of lysosomal membrane damage in blood and digestive cells isolated from Mytilus edulis exposed in vivo to the model hydrocarbon fluoranthene. In addition, the sensitivity of NRR as a biomarker of contaminant effect for isolated digestive cells, was compared to that of lysosomal latency, as an established biomarker of lysosomal damage, in tissue sections of digestive gland. The results of the NRR assay indicated a significant depression in the dye retention time following exposure to fluoranthene, and to its acetone vehicle, which was indicative of membrane failure. There was, however, no significant difference between the lysosomal retention times for the two cell types under investigation indicating a contaminant effect that is independent of the complement of the acid hydrolases within the lysosomes, and possibly their role within a particular cell type, and more toward a failure in a common controlling factor. The comparison of NRR and latency for digestive cell lysosomes, following fluoranthene exposure, showed that there was good agreement between the tests in terms of their ability to demonstrate a detrimental contaminant effect. The latency test, however, failed in contrast to the NRR assay to detect any effect resulting from exposure to the acetone vehicle alone.