Chromium(VI) reduction by ascorbate: Role of reactive intermediates in DNA damage in vitro

Diane M Stearns, K. D. Courtney, P. H. Giangrande, L. S. Phieffer, K. E. Wetterhahn

Research output: Contribution to journalArticle

53 Citations (Scopus)

Abstract

Reaction of chromium(VI) with one equivalent of ascorbate was studied by electron paramagnetic resonance spectroscopy in the presence of 0.10 M 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) at room temperature in 0.10 M (N-[2-hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid]) (HEPES) and 0.05 M tris(hydroxymethyl)aminomethane hydrochloride Tris-HCl) buffers (pH 7.0, room temperature). Chromium(V), ascorbyl radical, and carbon-based DMPO-radical adducts were observed. A higher level of Cr(V) was observed in HEPES buffer and a higher level of the DMPO-radical adducts was observed in Tris-HCl buffer. Chromium-DNA binding studies were carried out in vitro for calf thymus DNA incubated with Cr(VI) and ascorbate in both buffers at 37°C. Higher Cr-DNA binding was observed in HEPES buffer. DNA strand-break studies were carried out in vitro on pBR322 DNA incubated with Cr(VI) and ascorbate in both buffers at 37°C. Higher percent nicking was observed in Tris-HCl buffer. Addition of DMPO decreased nicking levels in Tris-HCl buffer. These results suggest that free radicals are more reactive than Cr(V) in producing DNA strand breaks and that Cr(V) will react with DNA to produce Cr-DNA adducts. The fact that buffer affects the nature of the reactive intermediates produced upon reduction of Cr(VI) may be related to differences in intracellular metabolism of Cr(VI) and resulting DNA damage observed in various cell culture systems and animal tissues in vivo.

Original languageEnglish (US)
Pages (from-to)21-25
Number of pages5
JournalEnvironmental Health Perspectives
Volume102
Issue numberSUPPL. 3
StatePublished - 1994
Externally publishedYes

Fingerprint

Tromethamine
DNA Damage
chromium
Buffers
HEPES
DNA
damage
Oxides
DNA Breaks
Chromium
oxide
Temperature
DNA Adducts
Electron Spin Resonance Spectroscopy
Free Radicals
Spectrum Analysis
Carbon
Cell Culture Techniques
In Vitro Techniques
chromium hexavalent ion

ASJC Scopus subject areas

  • Environmental Science(all)
  • Environmental Chemistry
  • Public Health, Environmental and Occupational Health

Cite this

Stearns, D. M., Courtney, K. D., Giangrande, P. H., Phieffer, L. S., & Wetterhahn, K. E. (1994). Chromium(VI) reduction by ascorbate: Role of reactive intermediates in DNA damage in vitro. Environmental Health Perspectives, 102(SUPPL. 3), 21-25.

Chromium(VI) reduction by ascorbate : Role of reactive intermediates in DNA damage in vitro. / Stearns, Diane M; Courtney, K. D.; Giangrande, P. H.; Phieffer, L. S.; Wetterhahn, K. E.

In: Environmental Health Perspectives, Vol. 102, No. SUPPL. 3, 1994, p. 21-25.

Research output: Contribution to journalArticle

Stearns, DM, Courtney, KD, Giangrande, PH, Phieffer, LS & Wetterhahn, KE 1994, 'Chromium(VI) reduction by ascorbate: Role of reactive intermediates in DNA damage in vitro', Environmental Health Perspectives, vol. 102, no. SUPPL. 3, pp. 21-25.
Stearns, Diane M ; Courtney, K. D. ; Giangrande, P. H. ; Phieffer, L. S. ; Wetterhahn, K. E. / Chromium(VI) reduction by ascorbate : Role of reactive intermediates in DNA damage in vitro. In: Environmental Health Perspectives. 1994 ; Vol. 102, No. SUPPL. 3. pp. 21-25.
@article{a85880079c414cc8af25e57bedc6be1f,
title = "Chromium(VI) reduction by ascorbate: Role of reactive intermediates in DNA damage in vitro",
abstract = "Reaction of chromium(VI) with one equivalent of ascorbate was studied by electron paramagnetic resonance spectroscopy in the presence of 0.10 M 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) at room temperature in 0.10 M (N-[2-hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid]) (HEPES) and 0.05 M tris(hydroxymethyl)aminomethane hydrochloride Tris-HCl) buffers (pH 7.0, room temperature). Chromium(V), ascorbyl radical, and carbon-based DMPO-radical adducts were observed. A higher level of Cr(V) was observed in HEPES buffer and a higher level of the DMPO-radical adducts was observed in Tris-HCl buffer. Chromium-DNA binding studies were carried out in vitro for calf thymus DNA incubated with Cr(VI) and ascorbate in both buffers at 37°C. Higher Cr-DNA binding was observed in HEPES buffer. DNA strand-break studies were carried out in vitro on pBR322 DNA incubated with Cr(VI) and ascorbate in both buffers at 37°C. Higher percent nicking was observed in Tris-HCl buffer. Addition of DMPO decreased nicking levels in Tris-HCl buffer. These results suggest that free radicals are more reactive than Cr(V) in producing DNA strand breaks and that Cr(V) will react with DNA to produce Cr-DNA adducts. The fact that buffer affects the nature of the reactive intermediates produced upon reduction of Cr(VI) may be related to differences in intracellular metabolism of Cr(VI) and resulting DNA damage observed in various cell culture systems and animal tissues in vivo.",
author = "Stearns, {Diane M} and Courtney, {K. D.} and Giangrande, {P. H.} and Phieffer, {L. S.} and Wetterhahn, {K. E.}",
year = "1994",
language = "English (US)",
volume = "102",
pages = "21--25",
journal = "Environmental Health Perspectives",
issn = "0091-6765",
publisher = "Public Health Services, US Dept of Health and Human Services",
number = "SUPPL. 3",

}

TY - JOUR

T1 - Chromium(VI) reduction by ascorbate

T2 - Role of reactive intermediates in DNA damage in vitro

AU - Stearns, Diane M

AU - Courtney, K. D.

AU - Giangrande, P. H.

AU - Phieffer, L. S.

AU - Wetterhahn, K. E.

PY - 1994

Y1 - 1994

N2 - Reaction of chromium(VI) with one equivalent of ascorbate was studied by electron paramagnetic resonance spectroscopy in the presence of 0.10 M 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) at room temperature in 0.10 M (N-[2-hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid]) (HEPES) and 0.05 M tris(hydroxymethyl)aminomethane hydrochloride Tris-HCl) buffers (pH 7.0, room temperature). Chromium(V), ascorbyl radical, and carbon-based DMPO-radical adducts were observed. A higher level of Cr(V) was observed in HEPES buffer and a higher level of the DMPO-radical adducts was observed in Tris-HCl buffer. Chromium-DNA binding studies were carried out in vitro for calf thymus DNA incubated with Cr(VI) and ascorbate in both buffers at 37°C. Higher Cr-DNA binding was observed in HEPES buffer. DNA strand-break studies were carried out in vitro on pBR322 DNA incubated with Cr(VI) and ascorbate in both buffers at 37°C. Higher percent nicking was observed in Tris-HCl buffer. Addition of DMPO decreased nicking levels in Tris-HCl buffer. These results suggest that free radicals are more reactive than Cr(V) in producing DNA strand breaks and that Cr(V) will react with DNA to produce Cr-DNA adducts. The fact that buffer affects the nature of the reactive intermediates produced upon reduction of Cr(VI) may be related to differences in intracellular metabolism of Cr(VI) and resulting DNA damage observed in various cell culture systems and animal tissues in vivo.

AB - Reaction of chromium(VI) with one equivalent of ascorbate was studied by electron paramagnetic resonance spectroscopy in the presence of 0.10 M 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) at room temperature in 0.10 M (N-[2-hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid]) (HEPES) and 0.05 M tris(hydroxymethyl)aminomethane hydrochloride Tris-HCl) buffers (pH 7.0, room temperature). Chromium(V), ascorbyl radical, and carbon-based DMPO-radical adducts were observed. A higher level of Cr(V) was observed in HEPES buffer and a higher level of the DMPO-radical adducts was observed in Tris-HCl buffer. Chromium-DNA binding studies were carried out in vitro for calf thymus DNA incubated with Cr(VI) and ascorbate in both buffers at 37°C. Higher Cr-DNA binding was observed in HEPES buffer. DNA strand-break studies were carried out in vitro on pBR322 DNA incubated with Cr(VI) and ascorbate in both buffers at 37°C. Higher percent nicking was observed in Tris-HCl buffer. Addition of DMPO decreased nicking levels in Tris-HCl buffer. These results suggest that free radicals are more reactive than Cr(V) in producing DNA strand breaks and that Cr(V) will react with DNA to produce Cr-DNA adducts. The fact that buffer affects the nature of the reactive intermediates produced upon reduction of Cr(VI) may be related to differences in intracellular metabolism of Cr(VI) and resulting DNA damage observed in various cell culture systems and animal tissues in vivo.

UR - http://www.scopus.com/inward/record.url?scp=0027986666&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027986666&partnerID=8YFLogxK

M3 - Article

C2 - 7843100

AN - SCOPUS:0027986666

VL - 102

SP - 21

EP - 25

JO - Environmental Health Perspectives

JF - Environmental Health Perspectives

SN - 0091-6765

IS - SUPPL. 3

ER -