An ultrastructural and morphometric study of the liver of normal and copper-poisoned sheep.

In sheep given copper (Cu) at the level of 10 ml of a 0.2% solution of CuSO4.5H2O/kg body weight, the volume density of nuclei and cytoplasm of hepatocytes increased and the volume density of the sinusoids and the space of Disse decreased. These changes were interpreted as an indication of cellular swelling. There was a significant increase in volume density, number, and absolute volume of lysosomes when Cu was given. The greatest increase in number occurred during the pre-hemolytic period (mean = 48 days), and the highest increase in volume occurred thereafter. Thus, the most extensive proliferation of lysosomes occurred in livers of the pre-hemolytic sheep, and the hemolytic sheep had the largest and heaviest lysosomes. The liver necrosis in sheep undergoing hemolysis was possible caused by hydrolytic enzymes released by the rupture of the enclosing lysosomal membranes. The significant increase in volume density of mitochondria observed in livers of sheep given Cu was due to an increase in volume (swelling) rather than an increase in number.