Fine structure of hepatocytes and hepatocellular carcinoma of the Atlantic tomcod, Microgadus tomcod (Walbaum)

Abstract

Abstract. The fine structure of livers from Atlantic tomcod, Microgadus tomcod (Walbaum), differed between samples from the Hudson and the Pawcatuck Rivers. The hepatocytes of fish from the Pawcatuck River were characterized by cords two cells wide separated by distinct blood sinuses. The hepatocytes contained moderate amounts of glycogen and lipid, rough endoplasmic reticulum, mitochondria and a central nucleus. Hepatocytes of samples from the Hudson River had ceroid plaques, extensive arrays of rough endoptasmic reticulum that were often distended, heavy deposits of lipid that deformed other organelles and no glycogen. The nucleus and cytoplasmic portion of hepatocellular carcinoma cells from the Hudson River were much larger than other hepatocytes and contained fewer fatty deposits, but still had lots of rough endoplasmic reticulum in varying degrees of distension. The pathological manifestations of the hepatocytes are consistent with damage due to exposure to toxic compounds and suggest that the high prevalence of hepatocellular carcinoma from the Hudson River tomcod is due to exposure to environmental carcinogens.