Arylsulphatase activity associated with phenanthrene induced digestive cell deletion in the marine mussel Mytilus edulis

Abstract

The acid hydrolase arylsulphatase has been localized at the ultrastructural level in digestive cells of the marine mussel Mytilus edulis for control and phenanthrene-treated (200 micrograms/l) animals. In untreated mussels the activity was generally restricted to the lysosomal-vacuolar system and the Golgi apparatus. It was associated with all types of vesicle, although not all individual vesicles were reactive. In heterolysosomes which were filled with precipitate the reaction product was most densely associated with the limiting membranes. Lipid inclusions commonly occurred in the digestive cells; these sometimes showed limited reaction for enzyme activity. The striking difference between normal and phenanthrene-treated samples was the presence in all treated animals of reaction product in the inter-cellular spaces and varying degrees of cytoplasmic activity in a number of digestive cells. This is interpreted as a sign of impending cell deletion. Sections for morphological examination showed evidence of increased digestive cell deletion in phenanthrene-treated mussels. The process results in release of membrane-bound bodies into the tubule lumen.