Compounds in urban air compete with 2,3,7,8-tetrachlorodibenzo-p-dioxin for binding to the receptor protein

Rune Toptgård, Göran Löfroth, Jan Carlstedt-Duke, Rabinder Kurl, Jan åke Gustafsson

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


Acetone extracts of filter-collected urban airborne particulate matter contain compounds which can competitively inhibit 2,3,7,8-[1,6-3H]tetra-chlorodibenzo-p-dioxin (TCDD) binding to the rat liver TCDD-receptor protein. The concentration of conventional polycyclic aromatic hydrocarbons (PAHs) or chlorinated dioxins and dibenzofurans cannot account for more than 1-30% of the observed competition for [3]HJTCDD binding to the receptor protein. The difference in potency between samples collected in urban areas during different periods of the year and a background sample is 25-400-fold. Collecting samples in the presence of increased concentrations of nitrogen dioxide, nitrous acid, nitric acid or ozone did not increase the amount of compounds with receptor affinity. However, with nitrogen dioxide and especially with nitric acid, a substantial increase of the mutagenic effects in the Ames Salmonella assay in the absence of mammalian activation as well as a degradation of several PAHs were noted. Affinity for the TCDD-receptor protein, mutagenicity in the absence of mammalian metabolic activation in the Ames Salmonella assay and PAH-content are characteristics of urban particulate matter showing the presence of compounds, that represent potential health risks. The compounds with affinity for the receptor may constitute a group of substances different from both conventional PAHs and directacting mutagens.

Original languageEnglish (US)
Pages (from-to)335-346
Number of pages12
JournalChemico-Biological Interactions
Issue number3
StatePublished - Sep 15 1983


  • 2,3,7,8-Tetrachlorodibenzo-p-dioxin
  • Air pollution
  • Mutagenicity
  • Polycyclic aromatic hydrocarbons
  • Receptor binding

ASJC Scopus subject areas

  • Toxicology


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