Ultrastructural alterations in the liver and kidney of white sea bass, Lates calcarifer, in acute and subchronic cadmium exposure.

Abstract

Ultrastructural alterations in the liver and kidney of 3-month-old white sea bass, Latescalcarifer, after cadmium exposure were studied by transmission electron microscopy (TEM). One group of fish was exposed to a cadmium concentration of 10 mg/L (acute) for 96 h in a static system, and another group was exposed to cadmium concentrations of 0.8 and 3 mg/L cadmium (subchronic) for 3 months in a recirculation closed system. Ultrastructural alterations observed in the hepatocytes included mitochondrial condensation, swelling, and lysis. The rough endoplasmic reticulum (RER) showed dilation, fragmentation, and vesiculation. After subchronic exposure there were numerous large lipid droplets and abundant stored glycogen. Ultrastructural alterations observed in the proximal tubules of the kidney included nuclear degeneration, condensation, and massive swelling of the mitochondria; RER fragmentation and vesiculation. Disorganized brush borders and increased numbers of large hydropic vacuoles and lysosomes were also observed.