Comparison of effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos

Our plain-English summary of Comparison of effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos, by E.G. Beck, P.F. Holt, N. Manojlović (British Journal of Industrial Medicine, 1972).

The study

• Authors: E.G. Beck, P.F. Holt, N. Manojlović
• Journal: British Journal of Industrial Medicine
• Published: 1972;29(3):280-6
• Cited by: 31 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Beck, E. G., Holt, P. F., and Manojlović, N. (1972).Brit. J. industr. Med.,29, 280-286. Comparison of effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos. The effects on macrophage cultures of glass fibre, glass powder, and chrysotile asbestos are compared. Glass fibre behaves like chrysotile in producing an increase in cell membrane permeability in cultured macrophages. This is demonstrable by the increase in lactic dehydrogenase activity in the supernatant fluid. The metabolism, measured by lactate production, is not reduced as it is when quartz is phagocytosed. Glass powder behaves like the inert dust corundum, producing little change in the number of cells stained by erythrosin B and a small increase in lactate dehydrogenase activity, both being in the range of the control. There is an increase in lactate production as a result of higher metabolism due to phagocytosis. Dusts may produce two basic effects, namely a toxic effect and change in cell membrane permeability. A non-specific effect on the cell membrane due to the slow and sometimes incomplete process of ingestion of long fibres is probably a function of the morphology, particularly the length of the fibres. A primary specific effect induced by some dusts immediately follows contact with the cell membrane.

In plain English

This laboratory experiment compared how several dusts affected macrophages (scavenger cells) taken from the lungs (alveolar) and abdominal cavity (peritoneal) of guinea-pigs and grown in culture. The dusts were Rhodesian chrysotile asbestos, glass fibre, glass powder made from the same lump glass, quartz (a toxic comparison) and corundum (an inert comparison). Over 20 hours the authors measured how leaky the cell membranes became, by counting cells stained with the dye erythrosin B and measuring the enzyme LDH released into the fluid. They measured cell metabolism by lactate production. Chrysotile and glass fibre both increased membrane leakiness. After 20 hours, 37% of peritoneal cells were stained with chrysotile and 48% with glass fibre, against 7% with no dust. Quartz stained all cells and cut lactate production, but neither fibre reduced it. Glass powder behaved like corundum. Microscopy showed that stained cells had often only partly swallowed long fibres. The authors concluded that fibre shape, not chemical composition, was responsible for the membrane change. They noted that in flat cell layers some fibres never touch the cells.

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: Laboratory (in vitro) experiment on cultured animal cells
• Who was studied: Alveolar (lung) and peritoneal (abdominal) macrophages from guinea-pigs, grown as monolayer cultures with 4 to 5 x 10^6 cells per tube. Each table value is the average of four experiments.
• Exposure: High-grade Rhodesian chrysotile; commercial glass fibre (1 to 20 micrometres long, 0.25 to 1.0 micrometres in diameter); glass powder (under 3 micrometres) from the same lump glass; quartz DQ 12 (toxic control); corundum (inert control); and cultures with no dust. Dust was added at 75 micrograms per 10^6 cells, with or without 5% homologous serum, and effects were measured at 3, 6 and 20 hours.
• Main results:
  • Peritoneal macrophages: chrysotile increased the number of cells stained by erythrosin and the amount of LDH released, but lactate production rose.
  • Peritoneal macrophages: glass fibre also increased membrane permeability. At 3 and 6 hours its values were lower than chrysotile's, but at 20 hours they were almost the same.
  • Peritoneal macrophages, percentage of cells stained by erythrosin at 3, 6 and 20 hours: chrysotile 10, 24 and 37; glass fibre 8, 17 and 48. The no-dust controls were 3, 6 and 7, and glass powder was 7, 13 and 14.
  • Quartz greatly increased membrane permeability, with all cells stained at 20 hours, and caused a pronounced fall in lactate production.
  • Glass fibre, like chrysotile, did not reduce metabolism as measured by lactate production, unlike quartz.
  • Glass powder produced minimal changes in membrane permeability but increased lactate production, comparable to corundum.
  • Alveolar macrophages: the effects were qualitatively similar. Chrysotile and glass fibre stained a larger share of cells than in peritoneal macrophages. At 20 hours: chrysotile 53%, glass fibre 64%, glass powder 16%, no dust 11%.
  • Microscopy showed that long chrysotile fibres and glass fibres were incompletely ingested. Cells that only partly took in fibres appeared spindle-shaped.
  • Adding 5% guinea-pig serum made alveolar macrophages ingest dust faster and in greater amounts. With serum, the percentage of stained cells and LDH activity were raised.
• The authors' conclusion: The authors concluded that the membrane permeability change was linked to the process of taking in long fibres, and that the fibre's shape (particularly length), not its chemical composition, was responsible.
• Limitations the authors state:
  • The authors stated that the monolayer culture technique probably has disadvantages for fibrous dusts. Because the cells lie in a plane, some fibres do not contact cells and instead form a network in the medium above them.

Topics

Medical terms in this study, explained in our Lexicon: Macrophage, Chrysotile, Lactate Dehydrogenase (LDH), Phagocytosis.

Related studies

• Effects of chrysotile and acid-treated chrysotile on macrophage cultures — E.G. Beck, P.F. Holt, et al. (1971)
• Comparison of effects of glass fibre and glass powder on guinea-pig lungs — S.K. Botham, P.F. Holt (1973)
• 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)
• Response of perifused alveolar macrophages to glass fibers: effect of exposure duration and fiber length — G. Forget, M.J. Lacroix, et al. (1986)
• The effects of chrysotile asbestos dust on lung macrophages maintained in organ culture. An electron-microscope study — J.M. Davis (1967)
• Cytotoxic effects of aramid fibres on rat pulmonary macrophages: comparison with chrysotile asbestos — J. Dunnigan, D. Nadeau, et al. (1984)

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