Reversible inhibition of DNA, RNA and protein synthesis in human cells by lead chloride

Lack of association of ?-aminolevulinic acid dehydratase genotype with cytogenetic damage in lead workers

“…Some studies (Cullen et al 1984;Kuo et al 1997) have reported that lead directly affects the human reproductive system and indirectly affects the DNA repair system. Furthermore, several studies (Skreb and Habazin-Novak 1975;Sirover and Loeb 1976;Popenoe and Schnaeler 1979;Hartwig et al 1990) have suggested that the interaction between lead and the polymerases or ligases involved in DNA excision 3) Non-smoking 21 6.1±0.7 (4.5-7.2) a ** 24 5.3±0.6 (4.3-6.3) b * 19 4.9±0.4 (4.2-5.6) Work duration 315 years 11 6.1±0.7 (4.5-7) 21 5.4±0.6 (4.3-6.3) --Work duration <15 years 15 6.3±0.6 (5.3-7.2) 10 5.5±0.5 (4.6-6.3) -- repair and inhibition of DNA repair constitutes a genotoxicity mechanism. DNA impairment and genotoxic effects may be magnified when repair is inhibited, as demonstrated in a study of UV-induced SCEs in cells exposed to different lead-ion levels (Hartwig et al 1990), which is consistent with the results of this study.…”

“…Any damage induced in cellular DNA may persist until circulating blood cells are stimulated to divide in culture. Studies involving human cells dosed with lead in vitro have indicated that lead ions may reduce the fidelity of DNA synthesis or repair (Skreb and Habazin-Novak 1975;Sirover and Loeb 1976) and inhibit DNA polymerase b and ligase activity (Popenoe and Schnaeler 1979). Hartwig et al (1990) reported an indirect mechanism of lead-induced genotoxicity in Chinese hamster V79 cells.…”