RESUMO
Formalin which is an aqueous solution of formaldehyde [HCHO] in water is used as disinfectant.Antiseptic and as a food preservative. This study was conducted on 40 adult albino rats to evaluate formalin ultrastructural effect on liver and kidney. Formalin was administered orally for three successive weeks at a daily dose of 50 mg/kg body weight in fresh cow's milk to the treated group [twenty rats] while the other twenty rats served as a control group which orally received milk only [1 cc / rat/day]. At the end of the experiment, light microscopic examination revealed dilatation, congestion of the central vein and hydropic degeneration of liver cells. Also hypercellularity of the glomeruli and cloudy swelling of renal tubules can be observed. Electron microscopic study showed, degeneration of most hepatocytes, mitochondriae were degenerated and cristae were absent. Also glomeruli with degenerated podocyte, proximal convoluted tubules with vacuolation of the cytoplasm and necrotic debris in the lumen of convoluted tubules can be detected. So, it can be concluded that the chronic oral administration of formalin causes toxic effects in the liver and kidneys of albino rats