TOXICOLOGICAL PROFILE FOR CHROMIUM - Davidborowski.com

CHROMIUM 2082. HEALTH EFFECTSet al. 1986; Kanematsu et al. 1980; Kortenkamp et al. 1996b; Nakamuro et al. 1978; Nestmann et al.1979; Olivier and Marzin 1987; Venitt and Levy 1974; Watanabe et al. 1998a). Forward mutations werenot induced in E. coli in one study (Nestmann et al. 1979). Negative or weakly positive results werereported in B. subtilis with chromium(III) (Kanematsu et al. 1980; Matsui 1980; Nakamuro et al. 1978;Nishioka 1975) and mostly negative results in E. coli (Llagostera et al. 1986; Olivier and Marzin 1987;Venier et al. 1989).A chromium(IV) ester was synthesized with 2,4-dimethyl-pentane-2,4-diol to examined its ability tocause DNA double strand breaks (Luo et al. 1996). Calf thymus DNA was reacted with thechromium(IV) complex (1.3 mg/mL) in the presence of 2 mM hydrogen peroxide for 6 days at pH 6.8.The results showed that the complex in the presence of hydrogen peroxide significantly damaged DNA bycausing double strand breaks. Neither chromium(IV) or hydrogen peroxide alone damaged DNA. Thekinetics of the reaction of chromium(IV) with hydrogen peroxide, showed the formation of proportionalamounts of hydroxyl radical with chromium(V). Use of a free radical scavenger prevented DNA strandbreaks. Other studies have shown that chromium(IV) is a better Fenton reagent than chromium(V) forreducing hydrogen peroxide and thus chromium(IV)-type damage by generating hydroxyl radicals mayalso be a contributor of in vivo genotoxicity.Studies in eukaryotic organisms indicated that chromium(VI) was genotoxic in Saccharomyces cerevisiae(Fukunaga et al. 1982; Nestmann et al. 1979; Singh 1983) and in Schizosaccharomyces pombe (Bonatti etal. 1976). One study demonstrated the genotoxicity of chromium(III) in S. cerevisiae (Bronzetti et al.1986). Sodium chromate induced DNA damage (DNA interstrand crosslinks, DNA strand breaks, DNAproteincrosslinks) in cultured chick embryo hepatocytes (Tsapakos et al. 1983a). The vast majority ofstudies reported genotoxic effects of chromium(VI) in mammalian cells in vitro (Briggs and Briggs 1988;DiPaolo and Casto 1979; Douglas et al. 1980; Elias et al. 1989b; Fornace et al. 1981; Gomez-Arroyo etal. 1981; Koshi 1979; Koshi and Iwasaki 1983; Kowalski et al. 1996; Levis and Majone 1979; MacRae etal. 1979; Majone and Levis 1979; Montaldi et al. 1987; Nakamuro et al. 1978; Newbold et al. 1979; Ohnoet al. 1982; Raffetto et al. 1977; Sarto et al. 1980; Stella et al. 1982; Sugiyama et al. 1986; Tsuda andKato 1977; Umeda and Nishimura 1979; Venier et al. 1982; Whiting et al. 1979; Yang et al. 1992).Although no increase in DNA damage was observed in Chinese hamster ovary cells exposed to leadchromate, probably due to the limited solubility of the tested compound (Douglas et al. 1980), an increasein chromosome aberrations was found in Chinese hamster ovary cells treated with lead chromate inanother study (Wise et al. 1993).