Histopathological and immunohistochemical studies in roundnose grenadier (Coryphaenoides rupestris) in the Skagerrak, North Sea

The aim of this study was to investigate whether the large-scale distribution of anthropogenic compounds in the Skagerrak deep sea gives rise to histopathological and immunohistochemical effects in fish. For this purpose, roundnose grenadier, Coryphaenoides rupestris, were examined from the Skagerrak (exposed site) and from a locality outside the Faroe Islands (reference site). The cytoplasm of hepatocytes offish from both areas was dominated by vacuoles, i.e. storage of either lipid or glycogen. Melanomacrophage centres (MMC) were also found. The major histological difference between the two groups was the increase of MMC in fish from the Skagerrak site. This finding was statistically confirmed by morphometry. Analysis of EROD showed that the enzyme was induced in the liver of fish from the Skagerrak. Immunohistochemical localization of cytochrome P450 1A in liver indicated positive staining of both vascular endothelial cells and hepatocytes. The induction of these parameters in fish from the Skagerrak cannot be excluded as being an effect of a large-scale contamination of anthropogenic compounds in the area.