Effects of Well-Defined Fibres on Red Blood Cells and Alveolar Macrophages

Our plain-English summary of Effects of Well-Defined Fibres on Red Blood Cells and Alveolar Macrophages, by M.C. Jaurand, L. Magne, J. Bigon, et al (1980).

The study

• Authors: M.C. Jaurand, L. Magne, J. Bigon, J. Goni
• Published: BIOLOGICAL EFFECTS OF MINERAL FIBRES (J.C. WAGNER, EDITOR), LYON: IARC SCIENTIFIC PUBLICATIONS, VOLUME 30., PP 441-450 (1980)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This laboratory (in vitro) study tested how different fibres affected two kinds of cells: human red blood cells from healthy donors and alveolar macrophages (lung scavenger cells) taken from rabbits. The fibres were UICC chrysotile, crocidolite and amosite asbestos, each either untreated or treated ('leached') with oxalic acid, plus nemalite and glass fibres. Chrysotile was also treated with sulfur dioxide. With red blood cells, chrysotile burst the cells (haemolysis) the most, and the two amphiboles, amosite and crocidolite, were poorly haemolytic. Acid treatment had opposite effects: it lowered the initial rate of haemolysis for chrysotile and raised it for the amphiboles. Sulfur dioxide did not highly modify haemolysis. In the macrophage tests, which measured enzyme release, the authors reported that amphiboles were cytotoxic (damaged the cells). Chrysotile mainly released one enzyme, beta-galactosidase. The authors concluded that reactivity differed greatly from fibre to fibre. They noted that animal experiments do not show these differences, and they proposed, as a hypothesis still to be tested, that the surface of amphibole fibres may be altered in place.

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 laboratory experiment on human red blood cells and rabbit alveolar macrophages
• Who was studied: Red blood cells from healthy human donors, and alveolar macrophages collected by lung lavage from rabbits. The macrophage experiments were done in duplicate, with three experiments per fibre. No dates or location of sampling given beyond the authors' Créteil laboratory.
• Exposure: UICC chrysotile A, crocidolite and amosite asbestos, untreated or treated with 0.1 N oxalic acid; nemalite; glass fibres (JM 104); chrysotile also treated with sulfur dioxide. Macrophages were exposed to concentrations from 50 to 1000 micrograms per ml.
• Main results:
  • Red blood cells: chrysotile was the most haemolytic fibre, and the two amphiboles (amosite and crocidolite) were poorly haemolytic.
  • Red blood cells: acid treatment had opposite effects on the two kinds of fibre. For chrysotile, the initial velocity of haemolysis decreased and maximal haemolysis was not highly modified. For the amphiboles, both increased.
  • Red blood cells: chrysotile, like nemalite, showed hyperbolic (curved) kinetics, while amosite and crocidolite released haemoglobin in a near-linear way.
  • Red blood cells: adsorption of sulfur dioxide did not highly modify the fibres' haemolytic reactivity.
  • Alveolar macrophages: the authors reported that the amphiboles were cytotoxic.
  • Alveolar macrophages: chrysotile caused a selective release of beta-galactosidase. At higher concentrations it also released LDH, but less than beta-galactosidase.
  • Alveolar macrophages: acid-treated chrysotile was cytotoxic, and acid-treated amphiboles seemed to release more beta-galactosidase than LDH.
  • Alveolar macrophages: amosite at 50 micrograms per ml was unreactive, but it released both enzymes at concentrations of more than 100 micrograms per ml.
  • Alveolar macrophages, after 6 hours with crocidolite at 1000 micrograms per ml: 37.4% of LDH and 26.5% of beta-galactosidase were released (Table 3).
  • Alveolar macrophages: adsorption of sulfur dioxide on chrysotile slightly increased the effects observed.
• The authors' conclusion: The authors concluded that the fibres' reactivity toward red blood cells and alveolar macrophages differed greatly from one fibre to another, and that acid treatment had opposite effects on chrysotile and amphiboles. They noted that the in vitro differences between chrysotile and the amphiboles are not seen in animal experiments, where all three induce mesotheliomas. They suggested, as a hypothesis that must be tested, that the surface of amphibole fibres may be altered in place.

Topics

Medical terms in this study, explained in our Lexicon: Alveolar Macrophage, UICC, Chrysotile, Crocidolite, Amosite, Amphibole Group, Macrophage.

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