Histopathological changes in gerbil liver and kidney after aluminum subchronic intoxication.

Young gerbil livers and kidneys were analyzed by means of light and electron microscope to assess the histopathological changes caused by prolonged systemic aluminum (Al) administration. The experimental group was injected with AlCl3 i.p. for 5 weeks, while litter mates received PBS as sham-injected controls or served as untouched controls. Mortality occurred in 33% of experimental and 12.5% of sham-injected groups. The animals were perfused intracardially with 1% glutaraldehyde plus 1% paraformaldehyde and samples of liver and kidneys were processed for aluminum and iron histochemistry and conventional light- and transmission electron microscopy. White deposits composed of cellular debris appeared on the surface of liver and kidneys and in the mesentery as a consequence of Al treatment. Adherences of Glisson capsule to the diaphragm, as well as scattered small foci of hepatocyte necrosis with non-caseificant microgranulomas and mild portal inflammation, developed in the experimental group. Sham-injected animals also exhibited these granulomas but to a lesser degree. Al deposits were found in experimental animal granulomas and inside macrophages cytoplasm scattered throughout the liver. Iron deposition appeared in pericentral hepatocytes of experimental animals, in granulomas and in portal spaces of the three groups of animals. Ultrastructurally, hepatocytes of experimental animals showed mitochondria hyalinization, disintegration of endoplasmic reticulum and clustering of ribosomes. Phagolysosomes appeared larger and occurred more frequently in both hepatocytes and Kupffer cells of experimental animals. In 2 out of the 6 experimental animals studied, tubular atrophy was present in the renal cortical region, the kidneys of the remaining animals appearing normal. Al and iron were found very occasionally in the kidney parenchyma of experimental animals, while isolated mesangial cells showed iron deposits in a few glomeruli of both experimental and the two groups of control animals.