Induction of chromosomal aberrations in bone marrow cells of asbestotic rats

Our plain-English summary of Induction of chromosomal aberrations in bone marrow cells of asbestotic rats, by N. Fatma, S.G. Khan, M. Aslam, et al (Environmental Research, 1992).

The study

• Authors: N. Fatma, S.G. Khan, M. Aslam, Q. Rahman
• Journal: Environmental Research
• Published: 1992;57(2):175-80
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

In the present study, cytogenetic effects of Indian chrysotile asbestos in rat bone marrow cells after 290 days of intratracheal inoculation (5 mg dust/0.5 ml normal saline), when it develops massive pulmonary fibrosis, were investigated. The pulmonary fibrosis was confirmed by both histopathological studies and increased collagen content in the lung of the treated animals. In the asbestotic rats a significant increase in chromosomal aberrations was recorded and a decrease in mitotic index of bone marrow cells. The types of chromosomal aberrations in these cells were chromatid gaps and breaks. The results indicate the significant cytogenetic changes in the bone marrow cells of asbestotic rats and also suggest that these changes directly or indirectly may be one of the biological events involved in eliciting the asbestos-mediated toxic responses.

In plain English

This was an animal experiment at the Industrial Toxicology Research Centre in Lucknow, India. Female albino rats received Indian chrysotile asbestos (5 mg in 0.5 ml of saline) placed directly into the windpipe. A control group received saline only. After 290 days, six rats from each group were killed and their bone marrow cells were examined for chromosome damage. The authors stated that the treated rats had lung fibrosis, but did not show these data. In the asbestos-treated rats, the overall incidence of chromosomal aberrations was 7.66%, compared with 4.16% in controls (600 cells scored per group, P less than 0.01). The authors described this as an increase of about 84%. The damage consisted of chromatid gaps and chromatid breaks. Bone marrow cell division (mitotic index) was lower in treated rats: 3.50 versus 5.83. The authors speculated that this chromosome damage may be one of the biological events behind asbestos toxicity. They said it remains to be investigated whether asbestos itself or asbestosis is responsible, and that the significance of the changes cannot be conclusively assumed.

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 (asbestos-treated rats compared with saline-treated control rats)
• Who was studied: Female albino rats from the Industrial Toxicology Research Centre animal colony, Lucknow, India; six rats per group (treated and control) were killed after 290 days for bone marrow study
• Exposure: Indian chrysotile asbestos from Cuddapah, Andhra Pradesh, India, with particle size below 30 micrometres, given intratracheally at 5 mg in 0.5 ml normal saline
• Main results:
  • Overall incidence of chromosomal aberrations in bone marrow cells was 7.66% (plus or minus 0.92 SE) in treated rats versus 4.16% (plus or minus 0.30 SE) in controls, with 600 cells scored per group (P less than 0.01). The authors described this as an increase of about 84%.
  • The aberrations were chromatid gaps (4.16 in treated rats versus 2.16 in controls, P less than 0.02) and chromatid breaks (3.5 in treated rats versus 2.00 in controls, P less than 0.05)
  • Mean mitotic index of bone marrow cells was 3.50 (plus or minus 0.23 SE) in treated rats versus 5.83 (plus or minus 0.31 SE) in controls, with 6000 cells scored per group (P less than 0.001)
  • Lung fibrosis in treated rats was reported as confirmed by histopathology and increased lung collagen; the data were not shown
  • No significant difference in body weight between treated and control rats at sacrifice (data not shown); the authors took this to mean the aberrations were not due to nutritional differences
• The authors' conclusion: The authors speculated that the chromosome-damaging effect in bone marrow cells of asbestotic rats may be one of the biological events that elicits the toxic response of asbestos fibers
• Limitations the authors state:
  • It is not yet known whether asbestos itself or asbestosis causes the chromosomal aberrations in bone marrow cells
  • The toxicological significance of the bone marrow changes cannot be conclusively assumed

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis, Chrysotile.

Medical terms in this study, explained in our Lexicon: Chrysotile, Pulmonary Fibrosis, Collagen, Mitotic Index.

Related studies

• Chromosomal aberrations induced by chrysotile and crocidolite in human lymphocytes in vitro — F. Valerio, M. de Ferrari, et al. (1983)
• Bone marrow alterations induced in mice with inhalation of chrysotile asbestos — G.A. Boorman, J.H. Dean, et al. (1984)
• Role of fibre characteristics on cytotoxicity and induction of anaphase/telophase aberrations in rat pleural mesothelial cells in vitro: correlations with in vivo animal findings — M. Yegles, X. Janson, et al. (1995)
• Specificity of asbestos-induced chromosomal aberrations in short-term cultured human mesothelial cells — K. Olofsson, J. Mark (1989)
• Attenuation of oxidative stress and chromosomal aberrations in cultured macrophages and pulmonary cells following self-sustained high temperature synthesis of asbestos — S. La Maestra, R.T. Micale, et al. (2020)
• Induction of micronuclei, hyperdiploidy and chromosomal breakage affecting the centric/pericentric regions of chromosomes 1 and 9 in human amniotic fluid cells after treatment with asbestos and ceramic fibers — E. Dopp, M. Schuler, et al. (1997)

Browse more research in Environmental Research, or return to medical research.