Department of Biological Sciences, Faculty of Science, University of Kuwait,
ABSTRACT
The morphological changes induced by sodium nitrite (NaNO2) in rat hepatocytes were studied by light and electron microscopy and the image analytical method. The experimental animals were divided into six groups, three of which were subjected to orally-administered NaNO2 in drinking water for 24 weeks at 0.05%, 0.1% and 0.2% concentrations. For comparison, two other groups were given either 0.05% of 7, 10-dimethylbenz[a]anthracence (DMBA) or 3% of olive oil, while the last group of animals was given the basal diet with no added contaminants, and served as a control. The structure of the liver from control and olive oil-treated groups appeared normal. The DMBA-treated group appeared similar to those of the NaNO2 ones. Morphological changes in the liver of NaNO2 animals included mild to extreme enlargement of hepatocytes and their nuclei, ballooning appearance, disintegration, increased cytoplasmic lipid droplets and extensive foci of necrosis. The sizes of the counted cells with their nuclei, and the weights of the animal bodies and the liver of all treatment groups, were significantly different from the control (p < 0.05). In contrast there was no difference based on variations in NO2 concentrations. Ultrastructurally, the changes in livers included the dilation of lumen, the loss of microvilli, a percentage damage in cell cytoplasm proliferation of SER and disorganization and stacking of RER the loss of mitochondrial cristae, an unusual increase in the size and number of lipid droplets, and glycogen depletion. These changes were similar with those of DMBA-treated groups. These alterations, which were morphometrically analyzed, may reflect a disturbance in the liver function following NaNO2 poisoning depending on the administered dosages, the length of time of exposure, and the strain of animals.
Keywords: DMBA, Hepatocyte, Morphometry, Nitrite, Poisoning, Rat