S.A. MOUSSA*, S.A. BASHANDY**
*Biophysics group, Department of Biochemistry, National Research Centre, Dokki, Cairo, Egypt
**Department of Pharmacology, National Research Centre, Dokki, Cairo, Egypt
Abstract. The present work is devoted to study the lead (Pb) toxicity in experimental wister male rats exposed to 2% lead acetate in drinking water and hence evaluate the risk on human workers who environmentally and occupationally exposed to similar toxicity. A total of thirty two wister male rats were equally divided into four groups, A, B, C, and D. Group A served as control group. Group B was exposed to 2% lead acetate in drinking water for one month. Group C, and D were exposed to the same condition as Group B for two months and three months respectively. Dielectric dispersion of hemoglobin (Hb) at frequency range of 20 – 3×106 Hz, hemoglobin absorption spectra, plasma alanine transaminase (ALT), aspirate transaminase (AST), alkaline phosphatase (ALP), total protein, and Cholesterol levels were carried out for all groups. The results indicated that exposure of animals to lead results in an increase in ALT, AST, ALP, and cholesterol levels in plasma of one, two and three months respectively indicating some damage in liver cell membrane. On the other hand, plasma total protein decrease significantly in the rats treated with lead. The dielectric results indicated that the studied hemoglobin of the lead treated groups has a dielectric dispersion in the frequency range used. The increase in the electrical conductivity and relaxation time for hemoglobin as compared to control could be attributed to the increased free radicals, reactive oxygen species, and peroxide radicals which results from lead toxicity, therefore there is an increase in the surface charge density of hemoglobin macromolecule. It was concluded that oral exposure of lead causes alterations in liver functions and biophysical parameters of hemoglobin.
Key words: Lead toxicity, dielectric dispersion, electrical conductivity, hemoglobin, ALT, AST, ALP.