Cytotoxic effects of quartz and chrysotile asbestos: in vitro interspecies comparison with alveolar macrophages

Our plain-English summary of Cytotoxic effects of quartz and chrysotile asbestos: in vitro interspecies comparison with alveolar macrophages, by J. Schimmelpfeng, A. Seidel (Journal of Toxicology and Environmental Health, 1991).

The study

• Authors: J. Schimmelpfeng, A. Seidel
• Journal: Journal of Toxicology and Environmental Health
• Published: 1991;33(2):131-40
• Cited by: 15 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Cytotoxic effects of DQ12 quartz and chrysotile asbestos on alveolar macrophages of different animal species were compared in vitro. The type of cell reaction toward the cytotoxic dusts was always the same: a loss of cell viability (trypan blue dye exclusion test) was accompanied by the release of cytoplasmic and lysosomal enzymes. The extent of cellular destruction depended upon the amount of dust applied. In the range of 50-100 micrograms/ml quartz or chrysotile asbestos, species-specific variations were observed in the sensitivity of the cells. At this concentration alveolar macrophages of dogs, monkeys, and human patients were damaged to a greater extent than the cells from rats and cattle. Simultaneous incubation of the cells with quartz and L-alpha-dipalmitoyl lecithin resulted in a reduction of the cytotoxic quartz effect. The extent of the protective effect varied according to the species. In the case of chrysotile asbestos no reduction of the fibers cytotoxicity was observed in the presence of L-alpha-dipalmitoyl lecithin.

In plain English

This laboratory study from Germany tested how DQ12 quartz and Canadian UICC chrysotile asbestos damaged alveolar macrophages, a type of lung immune cell, in culture dishes. Cells came from rats, cattle, dogs, monkeys and three human patients (one smoker and two with sarcoidosis), plus a human cell line called U937. Cells were exposed for 20 hours to up to 500 micrograms of dust per milliliter. In macrophages from all species the reaction was the same in kind: more dust meant fewer living cells, and cell death went along with the release of cell enzymes. Against chrysotile, cells from cattle, rats and the smoker were less sensitive, and cells from monkeys, dogs and the sarcoidosis patients were more sensitive. At 250 micrograms per milliliter, chrysotile caused less damage than quartz. Only monkey cells were destroyed completely by both dusts. U937 cells were resistant to chrysotile. A lung surfactant component (DPL) reduced quartz damage to varying degrees but did not reduce chrysotile's toxicity in any species. The authors concluded there were no principal or systematic species differences. They noted the study was descriptive and that dose-response tests were repeated only a few times.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: In vitro (cell culture) laboratory experiment comparing cells from different species
• Who was studied: Alveolar macrophages from rats, cattle, dogs (beagle), monkeys (Macaca fascicularis) and three human patients (one smoker and two sarcoidosis patients, one of them under steroid treatment), plus the human monocytic cell line U937. The work was done at the Kernforschungszentrum Karlsruhe, Germany. The number of animals per species is not legible in the text.
• Exposure: Canadian UICC chrysotile A asbestos. About 95% of the fibers were less than 0.5 micrometers in diameter and 97% were shorter than 5 micrometers. DQ12 standard quartz was used for comparison. Cells were exposed for 20 hours to 0 to 500 micrograms of dust per milliliter. In separate experiments, cells received 250 micrograms per milliliter of dust together with DPL (L-alpha-dipalmitoyl lecithin, a lung surfactant component) at 333 micrograms per milliliter.
• Main results:
  • In macrophages from all species, both dusts produced the same kind of reaction. Cell viability fell as the dust concentration rose. In the enzyme measurements, which were made at 250 micrograms per milliliter, the number of dead (trypan-blue-stained) cells correlated with release of the enzyme LDH.
  • Sensitivity to chrysotile asbestos differed by species. Cells from cattle, rat and the one human smoker were less sensitive. Cells from monkey, dog and the human sarcoidosis patients were more sensitive.
  • At 250 micrograms per milliliter, quartz damaged macrophages of all species almost completely: about 70-90% of total LDH and 30-50% of NAG were released into the medium. Chrysotile at the same concentration caused a smaller enzyme release and a smaller loss of viability. Only monkey macrophages were damaged completely by both dusts.
  • The human U937 cell line was less sensitive to quartz than the other cells and was resistant to chrysotile asbestos.
  • DPL reduced quartz toxicity, completely in cattle cells and least in human cells. DPL gave no protection against chrysotile asbestos in any species, and the authors reported no reduction even at higher DPL concentrations (data not shown).
• The authors' conclusion: The authors concluded that there were no principal or systematic differences among the species tested, and that the cells' response was qualitatively the same apart from the U937 cell line. They suggested that human myeloid cell lines are not suitable models for work with quartz or asbestos.
• Limitations the authors state:
  • Only limited amounts of quartz, chrysotile, and dog, monkey and human cells were available, so dose-response relationships were tested only a few times.
  • The study was primarily descriptive and could not explain the quantitative differences seen between species.

Topics

Medical terms in this study, explained in our Lexicon: Chrysotile, Alveolar Macrophage.

Related studies

• Response of bovine alveolar macrophages in vitro to welding fume particles — L.R. White, A.B. Marthinsen, et al. (1983)
• In vitro biodegradation of chrysotile fibres by alveolar macrophages and mesothelial cells in culture: comparison with a pH effect — M.C. Jaurand, A. Gaudichet, et al. (1984)
• Cytotoxic effects of aramid fibres on rat pulmonary macrophages: comparison with chrysotile asbestos — J. Dunnigan, D. Nadeau, et al. (1984)
• Glutathione release by pulmonary alveolar macrophages in response to particles in vitro — D.S. Boehme, K.R. Maples, et al. (1992)
• Kinetics of the bronchoalveolar leucocyte response in rats during exposure to equal airborne mass concentrations of quartz, chrysotile asbestos, or titanium dioxide — K. Donaldson, R.E. Bolton, et al. (1988)
• Leaching of chrysotile asbestos in human lungs. Correlation with in vitro studies using rabbit alveolar macrophages — M.C. Jaurand, J. Bignon, et al. (1977)

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