Abstract
Studies were carried out on the liver and intestine tissue of Clarias gariepinus after exposure to sublethal concentrations of LC50 lead nitrate for 20 days. Fish were distributed into four groups, control (0 mg/L, LC50 of Pb(NO3)(2)) and three groups exposed to 20, 40 and 60% of the LC50 of Pb(NO3)(2) (16.12, 32.24 and 48.37 mg/L respectively). Section of hepatic and intestine tissues showed the normal structure for control group. However, treated hepatic tissues of fish exhibited altered its characteristic architecture, with remarkably high vacuolation in hepatocytes and hepatoctolysis. Also, central vein was dilated and increased hemorrhage in the sections of almost samples from treated fish. Increased number of fibroblasts and Kuppffer cells were observed in the examined sections from treated fish when compared to the control. Therefore, fish treated with 60% LD50 of Pb(NO3)(2) observed the proliferation of fibrous in connective tissue particularly near sinusoids and substituting liver parenchyma. Therefore, intestinal sections from the different treated fish groups revealed an evident harmful to intestinal tissue, especially in enterocytes and structures of villi. Also, disturbed longitudinal and circular muscularis were observed, to abnormally dilated, lamina propria, was infiltrated with a huge numbers of inflammatory leukocytes. Mucous secreting goblet cells proliferated and multiplied in all exposed fish.