Seven-methylguanine adducts in DNA are normally present at high levels and increase on aging: Analysis by HPLC with electrochemical detection

Journal Article · Sat Oct 01 04:00:00 EDT 1988 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.85.20.7467· OSTI ID:5608096

Park, J W; Ames, B N ^[1]

---

1. Univ. of California, Berkeley (USA)

The 7-methylguanine adduct in the DNA of rat liver is determined as an indicator of exposure to exogenous and endogenous methylating agents. A method for the analysis of 7-methylguanine adducts has been developed by combining the selectivity of separation of reversed-phase HPLC with the specificity and high sensitivity of electrochemical detection. The sensitivity of the method is about 10,000-fold that of optical methods and is sufficient to determine the endogenous background of DNA methylation. DNA from the liver of normal young rats (6 months old) contains 7-methylguanine at a level of 1 residue per 31,000 bases in mitochondrial DNA and 1 residue per 105,000 bases in nuclear DNA. These levels increase about 2.5-fold in old rats (24 months old). The authors attribute this strikingly high level of adducts to endogenous methylation, which could contribute to aging and cancer.

• OSTI ID: 5608096
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 85:20; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ADDUCTS
AGE DEPENDENCE
AMINES
ANIMALS
AROMATICS
AZAARENES
BODY
CARCINOGENESIS
CELL CONSTITUENTS
CHEMICAL REACTIONS
CHEMISTRY
CHROMATOGRAPHY
DIGESTIVE SYSTEM
DNA
DNA ADDUCTS
ELECTROCHEMISTRY
ENZYMES
ESTERASES
GLANDS
GUANINE
HETEROCYCLIC COMPOUNDS
HYDROLASES
HYDROXY COMPOUNDS
LIQUID COLUMN CHROMATOGRAPHY
LIVER
MAMMALS
METHYLATION
MITOCHONDRIA
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOIDS
ORGANS
PATHOGENESIS
PHOSPHODIESTERASES
PURINES
RATS
RNA-ASE
RODENTS
SEPARATION PROCESSES
VERTEBRATES