Hemolysis by chrysotile asbestos fibers. I. Influence of the sialic acid content in human, rat, and sheep red blood cell membranes

Our plain-English summary of Hemolysis by chrysotile asbestos fibers. I. Influence of the sialic acid content in human, rat, and sheep red blood cell membranes, by J.P. Pelé, R. Calvert (Journal of Toxicology and Environmental Health, 1983).

The study

• Authors: J.P. Pelé, R. Calvert
• Journal: Journal of Toxicology and Environmental Health
• Published: 1983;12(4-6):827-40
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Complete removal of accessible sialic acids from human, rat, and sheep red cell membranes does not inhibit the hemolytic properties of chrysotile asbestos fibers. After 60 min of contact, the percentages of hemolysis are comparable between the treated and the nontreated groups. Nevertheless, with low concentrations of fibers the initial velocity of hemolysis of rat and sheep red blood cells is lower in the neuraminidase-treated group. Although sialic acids are not essential for the expression of the hemolytic activity of asbestos, we suggest that these acids could play a role during the first seconds or minutes of the hemolytic process by increasing the electrostatic attraction between the red blood cell membranes and the fibers. However, it is clear that asbestos fibers provoke hemolysis by acting on some other cell membrane component(s).

In plain English

In laboratory tests, the authors asked whether sialic acids, charged surface sugars, are needed for chrysotile asbestos fibers to burst red blood cells. They removed accessible sialic acids from human, rat and sheep red cells with the enzyme neuraminidase, then exposed treated and untreated cells to short Quebec 4T30 chrysotile fibers at 50 to 1000 micrograms per millilitre. Mean sialic acid content per 10^9 cells was 59.76 plus or minus 1.5 nmol in human, 32.77 plus or minus 1.20 in rat and 16.08 plus or minus 0.72 in sheep cells. Treatment slowed hemolysis of human cells at the highest fiber level only in the first minute, and cut the starting rate in sheep cells to about half. After 60 minutes, hemolysis was comparable in treated and untreated human cells and, in the main experiments, rat cells; rat cells treated with a second enzyme stayed lower at 1000 micrograms per millilitre. Treated sheep cells stayed lower, though nearly matching controls at 1000 micrograms per millilitre. The authors concluded that sialic acids are not essential and that the fibers act on other membrane components.

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 red blood cells. Cells treated with an enzyme (neuraminidase) to remove accessible sialic acids were compared with untreated cells for hemolysis by chrysotile fibers.
• Who was studied: Red blood cells from humans, rats and sheep. Sialic acid content was measured in cells from 3 human subjects, 4 rats and 3 sheep.
• Exposure: Short chrysotile fibers separated by sedimentation from Quebec 4T30 chrysotile. More than 90% of the fibers were shorter than 2.0 micrometres and the longest was 8 micrometres. Fiber concentrations were 50 to 1000 micrograms per millilitre.
• Main results:
  • Human red cells contained 59.76 plus or minus 1.5 nmol sialic acids per 10^9 cells, measured in cells from 3 subjects.
  • Rat red cells contained 32.77 plus or minus 1.20 nmol sialic acids per 10^9 cells, the mean of four animals.
  • Sheep red cells contained 16.08 plus or minus 0.72 nmol sialic acids per 10^9 cells, the mean of three assays.
  • Human red cells, 1000 micrograms of fibers per millilitre: the initial rate of hemolysis in enzyme-treated cells was much lower than in untreated cells, but only during the first minute of contact.
  • Human red cells: after 60 minutes of contact, the percentages of hemolysis were comparable between treated and untreated cells.
  • Rat red cells (enzyme from Clostridium perfringens): after 60 minutes of contact, the percentages of hemolysis were comparable between treated and untreated cells.
  • Rat red cells treated with enzyme from Vibrio cholerae: after 60 minutes, hemolysis was comparable to untreated cells at 200 micrograms of fibers per millilitre, but lower in treated cells at the higher concentration (1000 micrograms per millilitre).
  • Sheep red cells: in enzyme-treated cells the initial rate of hemolysis was reduced to about 50% of that of untreated cells, at all three fiber concentrations.
  • Sheep red cells: after 60 minutes of contact, the percentages of hemolysis were always lower in the enzyme-treated cells.
  • Sheep red cells, 1000 micrograms of fibers per millilitre: after 60 minutes, hemolysis in treated cells almost reached the values of untreated cells.
• The authors' conclusion: The authors concluded that sialic acids do not play an essential role in the hemolysis of red blood cells by chrysotile fibers. They suggested sialic acids might matter only in the first seconds or minutes of contact, and that the fibers react with other membrane components.
• Limitations the authors state:
  • The authors stated that more evidence is needed before concluding that asbestos fibers act mainly through the phospholipid components of the membrane.

Topics

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

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

Related studies

• Influence of the sialic acid content of the membrane on its susceptibility to chrysotile — J. Depasse (1982)
• A comparative study on the hemolytic action of short asbestos fibers on human, rat, and sheep erythrocytes — J.P. Pelé, R. Calvert (1983)
• Sialic acid mediates the initial binding of positively charged inorganic particles to alveolar macrophage membranes — J.E. Gallagher, G. George, et al. (1987)
• Interrelationship between hemolysis and lipid peroxidation of human erythrocytes induced by silicic acid and silicate dusts — S.V. Singh, Q. Rahman (1987)
• 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)
• Interactions of chrysotile asbestos with erythrocyte membranes — A.R. Brody, L.H. Hill (1983)

Browse more research in Journal of Toxicology and Environmental Health, or return to medical research.