The role of formaldehyde and S-chloromethylglutathione in the bacterial mutagenicity of methylene chloride

Graves, RJ; Callander, RD; Green, T

HERO ID

626445

Reference Type

Journal Article

Year

1994

Language

English

PMID

7508089

HERO ID 626445
In Press No
Year 1994
Title The role of formaldehyde and S-chloromethylglutathione in the bacterial mutagenicity of methylene chloride
Authors Graves, RJ; Callander, RD; Green, T
Journal Mutation Research
Volume 320
Issue 3
Page Numbers 235-243
Abstract Methylene chloride was less mutagenic in Salmonella typhimurium TA100/NG-11 (glutathione-deficient) compared to TA100, indicating that glutathione is involved in the activation of methylene chloride to a mutagen in bacteria. In rodents, the pathway of methylene chloride metabolism utilizing glutathione produces formaldehyde via a postulated S-chloromethylglutathione conjugate (GSCH2Cl). Formaldehyde is known to cause DNA-protein cross-links, and GSCH2Cl may act as a monofunctional DNA alkylator by analogy with the glutathione conjugates of 1,2-dihaloalkanes. The lack of sensitivity of Salmonella TA100 towards formaldehyde (Schmid et al., Mutagenesis, 1 (1986) No. 6, 427-431) suggests that GSCH2Cl is responsible for methylene chloride mutagenicity in Salmonella. In Escherichia coli K12 (AB1157), formaldehyde was mutagenic only in the wild-type, a characteristic shared with cross-linking agents, whereas 1,2-dibromoethane (1,2-DBE) was more mutagenic in uvrA cells (AB1886). Methylene chloride, activated by S9 from mouse liver, was mutagenic only in wild-type cells, suggesting a mutagenic role for metabolically derived formaldehyde in E. coli. Mouse-liver S9 also enhanced the cell-killing effect of methylene chloride in the uvrA, and a recA/uvrA double mutant (AB2480) which is very sensitive to DNA damage. This pattern was consistent with formaldehyde damage. However, a mutagenic role in bacteria for the glutathione conjugate of methylene chloride cannot be ruled out by these E. coli experiments because S9 fractions did not increase 1,2-DBE mutagenicity, suggesting lack of cell wall penetration by this reactive species. Rat-liver S9 did not activate methylene chloride to a bacterial mutagen or enhance methylene chloride-induced cell-killing, which is consistent with the carcinogenicity difference between the species.
Doi 10.1016/0165-1218(94)90050-7
Pmid 7508089
Wosid WOS:A1994MU51700008
Url http://www.sciencedirect.com/science/article/pii/0165121894900507
Is Certified Translation No
Dupe Override No
Comments Source: Web of Science WOS:A1994MU51700008
Is Public Yes
Language Text English
Keyword METHYLENE CHLORIDE; FORMALDEHYDE; GLUTATHIONE; 1,2-DIBROMOETHANE; ESCHERICHIA COLI; SALMONELLA TYPHIMURIUM
Is Peer Review Yes
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