Comparison of mutagenicity and calf thymus DNA adducts formed by the particulate and semivolatile fractions of vehicle exhausts

S.K. Pohjola (Corresponding Author), Maija Lappi, M. Honkanen, K. Savela

Research output: Contribution to journalArticleScientificpeer-review

23 Citations (Scopus)

Abstract

In this study we compared the ability of extractable organic material from particulate and semivolatile fractions of gasoline emission to induce mutations in bacteria and form adducts with calf thymus (CT) DNA with corresponding data obtained from diesel exhaust. Exhaust particles from gasoline‐powered passenger cars were collected on filters and semivolatile compounds were collected on polyurethane foam (PUF). The mutagenicity of the soluble organic fraction (SOF) was determined in Salmonella typhimurium strain TA98 and the DNA binding of aromatic compounds in the extracts was assessed by in vitro incubations with CT DNA and rat liver S9 (oxidative activation) or xanthine oxidase (reductive activation) followed by butanol‐enhanced 32P‐postlabeling analysis. Semivolatile fractions of gasoline emission collected on PUF formed more CT DNA adducts than filter extracts under all reaction conditions, but showed a lower mutagenic potential than the corresponding particulate samples. This suggests that the capacity of PUF to collect exhaust particle‐derived compounds and/or the efficiency of xanthine oxidase and enzymes in the rat liver S9 to activate these compounds to DNA binding metabolites was higher than expected. Gasoline extracts, benzo[a]pyrene and diesel particulate matter (SRM 1650) formed more S9‐mediated DNA adducts as their dose increased, although a linear dose–response was not observed for the gasoline exhausts. Lower concentrations of gasoline and diesel extracts bound to DNA with greater efficiency than did 8‐fold higher doses, suggesting complex interactions and/or an inhibition of S9 enzyme activities by the high doses. Diesel extracts formed higher levels of adducts than gasoline extracts, especially with the reductive activation system, suggesting that diesel extracts contain high levels of nitro‐polycyclic aromatic hydrocarbons (nitro‐PAHs). The higher direct‐acting Salmonella mutagenicity in diesel extracts in comparison with gasoline extracts is consistent with diesel extracts containing higher concentrations of nitro‐PAHs. The results of this study indicate that diesel extracts are more mutagenic and form more DNA adducts than gasoline extracts and that the effects of extract dose on DNA adduct formation are complex.
Original languageEnglish
Pages (from-to)26-36
Number of pages11
JournalEnvironmental and Molecular Mutagenesis
Volume42
Issue number1
DOIs
Publication statusPublished - 2003
MoE publication typeA1 Journal article-refereed

Fingerprint

Gasoline
DNA Adducts
Aromatic Hydrocarbons
Xanthine Oxidase
DNA
Vehicle Emissions
Particulate Matter
calf thymus DNA
Benzo(a)pyrene
Liver
Enzymes
Salmonella typhimurium
Salmonella
Bacteria
Mutation

Keywords

  • polycyclic aromatic hydrocarbons
  • PAH
  • mutagenicity
  • DNA adducts
  • 32P-postlabeling
  • gasoline
  • diesel
  • particulate
  • semivolatile fraction

Cite this

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title = "Comparison of mutagenicity and calf thymus DNA adducts formed by the particulate and semivolatile fractions of vehicle exhausts",
abstract = "In this study we compared the ability of extractable organic material from particulate and semivolatile fractions of gasoline emission to induce mutations in bacteria and form adducts with calf thymus (CT) DNA with corresponding data obtained from diesel exhaust. Exhaust particles from gasoline‐powered passenger cars were collected on filters and semivolatile compounds were collected on polyurethane foam (PUF). The mutagenicity of the soluble organic fraction (SOF) was determined in Salmonella typhimurium strain TA98 and the DNA binding of aromatic compounds in the extracts was assessed by in vitro incubations with CT DNA and rat liver S9 (oxidative activation) or xanthine oxidase (reductive activation) followed by butanol‐enhanced 32P‐postlabeling analysis. Semivolatile fractions of gasoline emission collected on PUF formed more CT DNA adducts than filter extracts under all reaction conditions, but showed a lower mutagenic potential than the corresponding particulate samples. This suggests that the capacity of PUF to collect exhaust particle‐derived compounds and/or the efficiency of xanthine oxidase and enzymes in the rat liver S9 to activate these compounds to DNA binding metabolites was higher than expected. Gasoline extracts, benzo[a]pyrene and diesel particulate matter (SRM 1650) formed more S9‐mediated DNA adducts as their dose increased, although a linear dose–response was not observed for the gasoline exhausts. Lower concentrations of gasoline and diesel extracts bound to DNA with greater efficiency than did 8‐fold higher doses, suggesting complex interactions and/or an inhibition of S9 enzyme activities by the high doses. Diesel extracts formed higher levels of adducts than gasoline extracts, especially with the reductive activation system, suggesting that diesel extracts contain high levels of nitro‐polycyclic aromatic hydrocarbons (nitro‐PAHs). The higher direct‐acting Salmonella mutagenicity in diesel extracts in comparison with gasoline extracts is consistent with diesel extracts containing higher concentrations of nitro‐PAHs. The results of this study indicate that diesel extracts are more mutagenic and form more DNA adducts than gasoline extracts and that the effects of extract dose on DNA adduct formation are complex.",
keywords = "polycyclic aromatic hydrocarbons, PAH, mutagenicity, DNA adducts, 32P-postlabeling, gasoline, diesel, particulate, semivolatile fraction",
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Comparison of mutagenicity and calf thymus DNA adducts formed by the particulate and semivolatile fractions of vehicle exhausts. / Pohjola, S.K. (Corresponding Author); Lappi, Maija; Honkanen, M.; Savela, K.

In: Environmental and Molecular Mutagenesis, Vol. 42, No. 1, 2003, p. 26-36.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Comparison of mutagenicity and calf thymus DNA adducts formed by the particulate and semivolatile fractions of vehicle exhausts

AU - Pohjola, S.K.

AU - Lappi, Maija

AU - Honkanen, M.

AU - Savela, K.

PY - 2003

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N2 - In this study we compared the ability of extractable organic material from particulate and semivolatile fractions of gasoline emission to induce mutations in bacteria and form adducts with calf thymus (CT) DNA with corresponding data obtained from diesel exhaust. Exhaust particles from gasoline‐powered passenger cars were collected on filters and semivolatile compounds were collected on polyurethane foam (PUF). The mutagenicity of the soluble organic fraction (SOF) was determined in Salmonella typhimurium strain TA98 and the DNA binding of aromatic compounds in the extracts was assessed by in vitro incubations with CT DNA and rat liver S9 (oxidative activation) or xanthine oxidase (reductive activation) followed by butanol‐enhanced 32P‐postlabeling analysis. Semivolatile fractions of gasoline emission collected on PUF formed more CT DNA adducts than filter extracts under all reaction conditions, but showed a lower mutagenic potential than the corresponding particulate samples. This suggests that the capacity of PUF to collect exhaust particle‐derived compounds and/or the efficiency of xanthine oxidase and enzymes in the rat liver S9 to activate these compounds to DNA binding metabolites was higher than expected. Gasoline extracts, benzo[a]pyrene and diesel particulate matter (SRM 1650) formed more S9‐mediated DNA adducts as their dose increased, although a linear dose–response was not observed for the gasoline exhausts. Lower concentrations of gasoline and diesel extracts bound to DNA with greater efficiency than did 8‐fold higher doses, suggesting complex interactions and/or an inhibition of S9 enzyme activities by the high doses. Diesel extracts formed higher levels of adducts than gasoline extracts, especially with the reductive activation system, suggesting that diesel extracts contain high levels of nitro‐polycyclic aromatic hydrocarbons (nitro‐PAHs). The higher direct‐acting Salmonella mutagenicity in diesel extracts in comparison with gasoline extracts is consistent with diesel extracts containing higher concentrations of nitro‐PAHs. The results of this study indicate that diesel extracts are more mutagenic and form more DNA adducts than gasoline extracts and that the effects of extract dose on DNA adduct formation are complex.

AB - In this study we compared the ability of extractable organic material from particulate and semivolatile fractions of gasoline emission to induce mutations in bacteria and form adducts with calf thymus (CT) DNA with corresponding data obtained from diesel exhaust. Exhaust particles from gasoline‐powered passenger cars were collected on filters and semivolatile compounds were collected on polyurethane foam (PUF). The mutagenicity of the soluble organic fraction (SOF) was determined in Salmonella typhimurium strain TA98 and the DNA binding of aromatic compounds in the extracts was assessed by in vitro incubations with CT DNA and rat liver S9 (oxidative activation) or xanthine oxidase (reductive activation) followed by butanol‐enhanced 32P‐postlabeling analysis. Semivolatile fractions of gasoline emission collected on PUF formed more CT DNA adducts than filter extracts under all reaction conditions, but showed a lower mutagenic potential than the corresponding particulate samples. This suggests that the capacity of PUF to collect exhaust particle‐derived compounds and/or the efficiency of xanthine oxidase and enzymes in the rat liver S9 to activate these compounds to DNA binding metabolites was higher than expected. Gasoline extracts, benzo[a]pyrene and diesel particulate matter (SRM 1650) formed more S9‐mediated DNA adducts as their dose increased, although a linear dose–response was not observed for the gasoline exhausts. Lower concentrations of gasoline and diesel extracts bound to DNA with greater efficiency than did 8‐fold higher doses, suggesting complex interactions and/or an inhibition of S9 enzyme activities by the high doses. Diesel extracts formed higher levels of adducts than gasoline extracts, especially with the reductive activation system, suggesting that diesel extracts contain high levels of nitro‐polycyclic aromatic hydrocarbons (nitro‐PAHs). The higher direct‐acting Salmonella mutagenicity in diesel extracts in comparison with gasoline extracts is consistent with diesel extracts containing higher concentrations of nitro‐PAHs. The results of this study indicate that diesel extracts are more mutagenic and form more DNA adducts than gasoline extracts and that the effects of extract dose on DNA adduct formation are complex.

KW - polycyclic aromatic hydrocarbons

KW - PAH

KW - mutagenicity

KW - DNA adducts

KW - 32P-postlabeling

KW - gasoline

KW - diesel

KW - particulate

KW - semivolatile fraction

U2 - 10.1002/em.10172

DO - 10.1002/em.10172

M3 - Article

VL - 42

SP - 26

EP - 36

JO - Environmental and Molecular Mutagenesis

JF - Environmental and Molecular Mutagenesis

SN - 0893-6692

IS - 1

ER -