The efficacy of 2-Mercapto propionyglycine in management of lead toxicity in rats with carbon tetrachloride-induced hepatic disorder was evaluated at two level of intoxication; chronic (5 and 50 mg Pb/kg/dayx30) and one acute dose (LD50 and 1/2 LD50). 2-MPG was given at a dose regimen of 50 mg/kg/dayx30. The LD50 of lead for normal and for hepatic disordered rats as well as lead accumulation in hepatocytes and its impact on liver functions were the main criteria to monitor the efficacy of treatment. The study showed that lead had additive toxic stress to rats with liver disordered than to normal ones where it displayed an LD50 of 1950 mg/kg for cirrhotic (hepatic disordered) rats compared to 3200 mg/kg for the normal ones. Significant accumulation of lead in hepatic cells with liver enlargement in hepatic disordered rats was recorded. Lead intoxication displayed further disorders in hepatic functions compared with non-intoxicated ones. More reductions in hepatic enzyme activities of 5'-nucleotidase, acetyl cholinesterase and aminotransferases in liver tissue were observed. Acetyl cholinesterase and 5'-nucleotidase in serum showed further decreased activities, while more elevations in hepatic alkaline phosphatase in addition to serum aminotransferases and alkaline phosphatase activities were detected. The toxic effects of lead were found to be more severe in acute rather than in chronic administration. Administration of 2-MPG showed appreciable protective effect against lead toxicity in hepatic disordered rats as manifested by marked reductions of the hepatic disorders and tissue lead accumulation in addition to improvement in relative liver weights.
Key words: 2-Mercapto propionyglycine, Lead pollution, Heavy metals, hepatic disorder
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