Biochemical changes and pulmonary response of guinea pigs to asbestos dust

Our plain-English summary of Biochemical changes and pulmonary response of guinea pigs to asbestos dust, by J. Singh, M.U. Beg, J.L. Kaw, et al (Acta Pharmacologica et Toxicologica, 1976).

The study

• Authors: J. Singh, M.U. Beg, J.L. Kaw, P.N. Viswanathan, S.H. Zaidi
• Journal: Acta Pharmacologica et Toxicologica
• Published: 1976;39(1):77-86
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The biochemical and histopathological changes in lungs of guinea pigs were studied 120 days after intratracheal injection of three varieties of asbestos dusts, viz. chrysotile, amosite and anthophyllite. The salient histopathological features observed were the development of dust cell lesions in the lungs of animals exposed to the different varieties of asbestos. Maximum fibrosis and minimal asbestos body formation was observed in animals exposed to chrysotile and anthophyllite, respectively. With amosite and anthophyllite the development of diffuse interstitial fibrosis ensued, accompanied by well developed asbestos body formation in the amosite exposed animals. Biochemical studies revealed significant alterations in various phosphorylated compounds, an accumulation of orthophosphate and depletion of esters and nucleotides being very marked. RNA content increased significantly in the amosite treated group while the nucleic acid content remained unaltered in the chrysotile group.

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

In plain English

In this animal experiment from a research centre in Lucknow, India, female guinea pigs (ten per dust) received a single injection into the windpipe of 50 mg of chrysotile, amosite or anthophyllite asbestos from Indian mines. Control animals received saline. After 120 days the authors examined the lungs under the microscope and measured lung weight, collagen and phosphorus compounds. All three dusts produced dust-cell lesions. Chrysotile produced cellular nodules and the most fibrosis, and only chrysotile significantly raised lung collagen. Amosite produced diffuse interstitial fibrosis with well-developed asbestos bodies. Anthophyllite produced a similar response with the least asbestos body formation. Fresh lung weight rose by 21% (anthophyllite), 30% (amosite) and 36% (chrysotile). Total phosphate did not change significantly. Inorganic phosphorus rose by 54% with chrysotile and 60% with amosite, while some phosphate esters and nucleotides fell. RNA rose by 27% with amosite. The authors concluded that the three dusts produced different biochemical and tissue responses. The lung weight and collagen figures are means of six animals per group, while the phosphorus figures are means of six determinations.

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: single intratracheal injection of asbestos dust in guinea pigs, with lung tissue and biochemistry examined 120 days later and compared with saline-injected controls
• Who was studied: Female guinea pigs weighing 400-450 g, ten per dust, plus saline-injected controls. Table 1 (lung weight and collagen) reports means of six animals. Tables 2 and 3 (phosphorus fractions) report means of six determinations.
• Exposure: Chrysotile, amosite or anthophyllite asbestos from Indian mines, fibre size below 30 microns. Each animal received a single intratracheal dose of 1.5 ml saline suspension containing 50 mg of dust. Controls received 1.5 ml of saline only.
• Main results:
  • Fibrosis was greatest with chrysotile; asbestos body formation was least with anthophyllite.
  • Amosite and anthophyllite produced diffuse interstitial fibrosis, with well-developed asbestos bodies in the amosite group.
  • Compared with controls, fresh lung weight increased significantly by 21% (anthophyllite), 30% (amosite) and 36% (chrysotile).
  • Lung collagen increased significantly only in the chrysotile group (P less than 0.05).
  • Total lung phosphate did not change significantly in the asbestos-treated groups.
  • Chrysotile group: orthophosphorus rose 54% (P less than 0.01). Acid-labile phosphorus fell 30% and nucleotide labile phosphorus fell 44% (P less than 0.01).
  • Amosite group: orthophosphorus rose 60% (P less than 0.01).
  • Anthophyllite group: nucleotide labile phosphorus rose 66% (P less than 0.01).
  • Amosite group: RNA rose 27% and DNA fell 13%.
  • Chrysotile group: nucleic acid content was unchanged.
  • Anthophyllite group: DNA rose 16% and RNA rose 12%, both significantly.
• The authors' conclusion: The authors concluded that the three dusts produced different qualitative or quantitative responses, both in some biochemical measures and in the lung tissue changes.

Topics

Medical terms in this study, explained in our Lexicon: Chrysotile, Amosite, Anthophyllite, Fibrosis, Asbestos Body Formation, Interstitial Fibrosis.

Related studies

• Lung cell reactions in guinea pigs after inhalation of asbestos (amosite) — M. Sjöstrand, R. Rylander, et al. (1989)
• Asbestos-body formation in the lungs of rats and guinea-pigs after inhalation of anthophyllite — S.K. Botham, P.F. Holt (1972)
• Failure of macrophage activation to induce pulmonary fibrosis in asbestos-exposed guinea-pigs — R.J. Emerson, P.J. Cole (1983)
• Biochemical changes in guinea pig lungs due to amosite asbestos — V. Misra, Q. Rahman, et al. (1978)
• The calcification of fibrous pleural lesions produced in guinea-pigs by the injection of chrysotile asbestos dust — J.M. Davis (1971)
• The development of glass-fibre bodies in the lungs of guinea-pigs — S.K. Botham, P.F. Holt (1971)

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