Inhibition by phospholipids of haemolytic action of asbestos

Our plain-English summary of Inhibition by phospholipids of haemolytic action of asbestos, by M.C. Jaurand, L. Magne, J. Bignon (British Journal of Industrial Medicine, 1979).

The study

• Authors: M.C. Jaurand, L. Magne, J. Bignon
• Journal: British Journal of Industrial Medicine
• Published: 1979;36(2):113-6
• Cited by: 31 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Haemolysis by asbestos fibres results from an increase in membrane permeability and not from rupture of red blood cells (RBC). The effect of chrysotile asbestos on RBC is at least partly, if not completely, attributable to lipid extraction and adsorption on to the fibres. This was suggested by the hyperbolic relationship between the haemolytic activity of chrysotile and the relative concentration of both chrysotile and RBC. Moreover, it was shown that pre-incubation of chrysotile with lipids, either as RBC membranes or with pure lipids in the form of liposomes, prevents haemolysis.

In plain English

This was a laboratory (test-tube) study, not a study of people exposed to asbestos. The authors mixed human red blood cells with standard UICC samples of chrysotile and crocidolite asbestos and measured haemolysis (haemoglobin release from the cells). The highest level of haemolysis, reached after 5 to 15 minutes, depended on the relative amounts of chrysotile and red cells, not on their absolute amounts. Expressed as the ratio of chrysotile surface to red-cell surface, 50% haemolysis occurred at a ratio of 0.32. Complete haemolysis occurred only with a large excess of chrysotile surface. When chrysotile was first mixed with red-cell membranes or with artificial lipid particles (liposomes), later haemolysis was prevented. Added latex particles had no such effect. With 1 mg/ml chrysotile and 5% red cells, 0.18 mg of lipid gave 80% inhibition when added as liposomes and 99-100% when added as red-cell membranes. In one test, 2 mg of crocidolite pre-incubated with 0.41 mg of the phospholipid dipalmitoyl phosphatidyl choline caused no haemolysis. The authors concluded that chrysotile's effect on red cells is at least partly, if not completely, caused by lipids being extracted from cell membranes and binding to the fibres.

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 human red blood cells exposed to asbestos fibres
• Who was studied: Human red blood cells from blood collected in citrate; the number of donors is not stated. Laboratory in Creteil, France.
• Exposure: UICC reference samples of chrysotile (fibres on average less than 5 micrometres long) and crocidolite (less than 4 micrometres), some pre-incubated with red-cell membranes or with liposomes made of dipalmitoyl phosphatidyl choline alone or mixed with cholesterol and dicetyl phosphate
• Main results:
  • For chrysotile, maximal haemolysis depended on the relative concentration of chrysotile and red cells, not on their absolute concentration
  • 50% haemolysis was obtained at a chrysotile-surface to red-cell-surface ratio (R) of 0.32 (printed '0-32' in the scan)
  • Complete haemolysis was obtained only with a large excess of chrysotile surface (the ratio is printed '2 5' in the scan, probably 2.5)
  • Pre-incubating chrysotile with red-cell membranes (ghosts) or liposomes prevented subsequent haemolysis
  • Adding latex particles to mimic the presence of ghosts or liposomes did not change haemolysis
  • When the red cells, rather than the fibres, were pre-incubated with ghosts or liposomes, the inhibition was smaller
  • Pre-incubating chrysotile with an amount of red-cell membrane matching the cells lysed by untreated fibres gave 95-100% inhibition
  • With 5% red cells and 1 mg/ml chrysotile pre-incubated with 0.18 mg of lipids, inhibition was 80% with pure phospholipid liposomes and 99-100% with red-cell membrane (ghost) lipids
  • No haemolysis was seen when 2 mg of crocidolite was pre-incubated with 0.41 mg of dipalmitoyl phosphatidyl choline
• The authors' conclusion: The authors concluded that haemolysis by chrysotile is a self-inhibiting process. In their view, the increase in red-cell membrane permeability is at least partly, if not completely, caused by lipid extraction from the membrane and adsorption of the lipids onto the fibres, and the protective effect appears mainly attributable to lipids.

Topics

Medical terms in this study, explained in our Lexicon: Chrysotile.

Related studies

• Chemical and photoelectron spectrometry analysis of the adsorption of phospholipid model membranes and red blood cell membranes on to chrysotile fibres — M.C. Jaurand, J.H. Thomassin, et al. (1980)
• Haemolytic activity of asbestos and other mineral dusts — G. Macnab, J.S. Harington (1967)
• A comparative study on the hemolytic action of short asbestos fibers on human, rat, and sheep erythrocytes — J.P. Pelé, R. Calvert (1983)
• Changes in lipid ordering of model phospholipid membranes treated with chrysotile and crocidolite asbestos — E.G. Gendek, A.R. Brody (1990)
• Mechanism of haemolysis by chrysotile fibres — M.C. Jaurand, L. Magne, et al. (1983)
• The prevention of asbestos-induced hemolysis — R. Desai, P. Hext, et al. (1975)

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