Involvement of alveolar macrophages in the formation of 8-oxodeoxyguanosine associated with exogenous particles in human lungs

Hiroshi Tokiwa, Nobuyuki Sera, Yoichi Nakanishi

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Lung specimens were collected from 161 nonsmoking male patients with carcinoma to determine the deposition of carbon particles and oxidative damage in lung tissues. Morphologically, carbon particles deposited in human lungs with carcinoma were similar to those of diesel exhaust like particles, and mass of particles showed a significant increase with the increasing age of the patients. An increasing age of patient with carcinomas was also associated with 8-oxodeoxyguanosine (8-oxo-dG) formation, which was analyzed using the high-performance liquid chromatography (HPLC) electrochemical detection method. In addition, it was found that 8-oxo-dG increased in cancerous tissues rather than in noncancerous ones. To determine whether particles in lung tissues were associated with 8-oxo-dG formation, carbon particles deposited in lung tissues were partially purified by cycling of alkali fusion with 1 M KOH; mutagenic chemicals in particles were extracted and excluded by removal with an equal volume of benzene/methanol and dichloromethane. It was also found that 8-oxo-dG was formed by nonmutagenic particles, and enhanced in the in vivo test using mouse rather than in vitro using RAW 254.7 tissue cultured cells. The 8-oxo-dG formation in vivo was due to the fact that hydroxyl radicals might be involved with phagocytosis of nonmutagenic particles in inflammatory cells, and the mutation was induced by hydroxylation of guanine residue on DNA. These results were also demonstrated by the occurrence of alveolar macrophages and neutrophils after intratracheal instillation of particles. These observations suggest that small particles from lung cancer patients further promote oxidative damage when used to treat the mouse lung. Especially, particles from which organic chemicals were removed were highly reactive to oxidative damage and formed 8-oxo-dG.

Original languageEnglish
Pages (from-to)577-585
Number of pages9
JournalInhalation Toxicology
Volume17
Issue number11
DOIs
Publication statusPublished - Sep 1 2005

All Science Journal Classification (ASJC) codes

  • Toxicology
  • Health, Toxicology and Mutagenesis

Fingerprint Dive into the research topics of 'Involvement of alveolar macrophages in the formation of 8-oxodeoxyguanosine associated with exogenous particles in human lungs'. Together they form a unique fingerprint.

  • Cite this