Formation of pseudo-asbestos bodies on sized glass fibres in the hamster lung

Our plain-English summary of Formation of pseudo-asbestos bodies on sized glass fibres in the hamster lung, by A. Holmes, A. Morgan, W. Davison (The Annals of Occupational Hygiene, 1983).

The study

• Authors: A. Holmes, A. Morgan, W. Davison
• Journal: The Annals of Occupational Hygiene
• Published: 1983;27(3):301-13
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Sized glass fibres, 3 µm in diameter and with lengths ranging from 10 to 100 µm, were administered to hamsters by intratracheal instillation. Animals were killed serially and fibres extracted from their lungs by hypochlorite digestion. Determinations were made of fibre dimensions with the light microscope and whether they were uncoated, partially or fully coated. As shown in previous studies with rats, the longer fibres dissolved more rapidly than the short, but all fibres dissolved more rapidly in the hamster than in the rat lung. Partially coated fibres were detected after 1 month for the 60 and 100µm and after 2 months for the 10 and 30 µm. There were wide variations in the frequency of coated fibres in different animals killed at the same time, but it tended to increase up to 5 months and then to decline. It was clear that the coating of glass fibres did not prevent their dissolution.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

In plain English

This was an animal experiment at the Atomic Energy Research Establishment, Harwell, UK. The authors placed sized glass fibres into the lungs of Syrian golden hamsters through the windpipe. The fibres were nominally 3 micrometres thick and 10, 30, 60 or 100 micrometres long, and each size went to about 24 hamsters. Animals were killed at intervals, and the recovered fibres were classed as uncoated, partially coated or fully coated, forming 'pseudo-asbestos bodies'. A smaller group received anthophyllite asbestos for comparison. At 1 month, no coated fibres were seen for the 10 and 30 micrometre fibres, while an average of 4.5% of the 60 and 15.8% of the 100 micrometre fibres were coated. Coating varied widely between animals killed at the same time. Fibres under 10 micrometres long did not become coated. Only the 30 micrometre fibres exceeded 10% fully coated. The glass fibres dissolved in the lung, faster in hamsters than in rats. The authors concluded that coating followed a similar time course to anthophyllite but did not prevent glass fibres dissolving.

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: Animal experiment: intratracheal instillation of fibres into hamsters, with animals killed at intervals and fibres recovered from lung tissue for light-microscope examination
• Who was studied: Syrian golden hamsters, about 6 weeks old at dosing; about 24 hamsters per glass fibre sample, plus a smaller group given anthophyllite; Harwell, UK
• Exposure: 0.2 mg of sized glass fibres (nominal diameter 3 micrometres; nominal lengths 10, 30, 60 and 100 micrometres; supplied by the Thermal Insulation Manufacturers Association) per animal; for comparison, 0.2 mg of anthophyllite asbestos (UICC standard reference sample) in a smaller group
• Main results:
  • At 1 month no coated fibres were detected for the 10 and 30 micrometre glass fibres, but an average of 4.5% of the 60 micrometre and 15.8% of the 100 micrometre fibres were coated
  • The proportion of partially coated fibres varied considerably between hamsters killed at the same time
  • The proportion of partially coated fibres appeared to rise up to about 3-4 months and stay fairly constant to about 5 months, with an apparent later decline for the longer fibres
  • Only with the 30 micrometre fibres did fully coated fibres exceed 10% of the total
  • For the nominal 10 micrometre fibres at 3 months, when 29% of fibres were coated, fibres shorter than 10 micrometres did not become coated
  • The 30 and 60 micrometre glass fibres became thinner (dissolved) quite rapidly in the hamster lung, at a similar rate
  • Glass fibres dissolved much more rapidly in hamster lung than in rat lung (from the authors' earlier rat study): the median diameter of 60 x 3 micrometre fibres fell to below 1 micrometre after 8 months in the hamster, compared with 1.9 micrometres after 1 year in the rat
  • Coating of the glass fibres did not prevent their dissolution
  • In hamsters given anthophyllite, the first signs of coating were seen by 2 months, and after a year even the longest anthophyllite fibres (up to 150 micrometres) were fully coated
• The authors' conclusion: The authors concluded that in the hamster lung, pseudo-asbestos bodies formed on glass fibres on a similar time course to asbestos bodies on anthophyllite. Coating competed with fibre dissolution but did not appear to prevent the glass fibres from dissolving.
• Limitations the authors state:
  • The authors could not tell whether the fibre breakage seen at later times happened in the lung or was caused by the digestion procedure
  • The hypochlorite digestion method itself affects the diameter of glass fibres that have been in the lung for long periods
  • The longer fibres had two-peaked length distributions, but median lengths were calculated as if the distributions were log-normal, so length measurements were used only qualitatively
  • Coating measurements stopped at 8 months because many long fibres had dissolved completely or fragmented

Topics

Medical terms in this study, explained in our Lexicon: Asbestos Bodies.

Related studies

• Solubility of rockwool fibres in vivo and the formation of pseudo-asbestos bodies — A. Morgan, A. Holmes (1984)
• Chronic inhalation study of fiber glass and amosite asbestos in hamsters: twelve-month preliminary results — T.W. Hesterberg, C. Axten, et al. (1997)
• Pulmonary response of hamsters to fibrous glass: chronic effects of repeated intratracheal instillation with or without benzo[a]pyrene — V.J. Feron, P.M. Scherrenberg, et al. (1985)
• Differences in the biological effects of crocidolite asbestos and two glass fibres on epithelial lung cells — M. Aufderheide, M. Riebe-Imre, et al. (1994)
• The development of glass-fibre bodies in the lungs of guinea-pigs — S.K. Botham, P.F. Holt (1971)
• A comparison of the cytogenetic response to asbestos and glass fibre in Chinese hamster and human cell lines. Demonstration of growth inhibition in primary human fibroblasts — A.M. Sincock, J.D. Delhanty, et al. (1982)

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