Assessment of the Amount of Hepatohistopatological and Enzymatic Changes after Chronic Lead Intoxication In Utero and Throughout Life in Rat

In order to evaluate the functional changes of liver after lead intoxication, activity of enzymes, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP), as well as pathological changes of the liver were assessed in the present study. Male and female Albino Rats (40 in total) in five 8-rat groups were exposed to 0, 5, 10, 15, and 40mg lead acetate dissolved in 1 liter drinking water, from the onset of embryonic life to 16th week of life. At the end of 16th week, the animals were anesthetized with chloroform, and blood sampling from heart was performed. After serum separation for biochemical analysis, liver was taken out and fixed in 15% formalin for histopathological studies. Activity of ALT, AST, and ALP, as well as lead concentration of the serum samples were measured using spectrophotometrical method and graphite furnace atomic absorption, respectively. The tissue sections were histologically studied under light microscopy after staining by hematoxylin/eosin. The results were analyzed using analysis of variance and Tukey's test, and p<0.05 was considered significant. In this study, liver enzymes activities had direct relation with the serum lead concentration, and showed a significant increase compared to the control groups. Histological changes were observed as inflammation, lymphocyte infiltration to liver tissue, and liver cells necrosis. According to the results of this study, long-time exposure to lead results in dose- and time-dependent liver injury.