Electrophysiological Changes Induced by Asbestos Macrophage-Like Cells During Long-Term Culture

Our plain-English summary of Electrophysiological Changes Induced by Asbestos Macrophage-Like Cells During Long-Term Culture, by I.P. Gromley, M.O. Wright (1980).

The study

• Authors: I.P. Gromley, M.O. Wright
• Published: BIOLOGICAL EFFECTS OF MINERAL FIBRES (J.C. WAGNER, EDITOR), LYON: IARC SCIENTIFIC PUBLICATIONS, VOLUME 30., PP 435-439 (1980)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This was a laboratory experiment on cells grown in dishes, not a study of people. The authors exposed P388D1 cells, a permanent line of macrophage-like cells, to UICC samples of chrysotile, crocidolite and amosite asbestos, in culture medium either with or without serum, and recorded the cell membranes' electrical properties (membrane potential and input resistance) for up to about two days. Without serum, chrysotile caused a significant decline in both measures that was greatest at three hours, and amosite caused a marked rise that peaked at one hour. Without serum, crocidolite caused no statistically significant changes in either measure. With serum, chrysotile and amosite caused an early rise followed by a later decline. In the serum-containing medium, 60% of the chrysotile-exposed cells tested were dead by 48 hours, and 80% of the amosite-exposed cells tested were dead by 47 hours. With serum, crocidolite values swung up and down for six hours and then stayed similar to controls. Small waves of electrical activity in the cells became larger and more frequent with all three asbestos samples. The authors concluded that different fibres can cause different changes, suggesting that different mechanisms of cell damage are involved.

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 measuring the electrical properties of cultured cell membranes after exposure to asbestos
• Who was studied: P388D1 cells, a permanent macrophage-like cell line grown in culture (cell numbers not stated); work done in Edinburgh, UK
• Exposure: UICC samples of chrysotile, crocidolite or amosite asbestos, added in medium with or without serum (the serum had been conditioned on P388D1 cells first). Measurements ran up to about 48 hours. Doses are not given in the text.
• Main results:
  • Unexposed control cells had a mean membrane potential of 11.0 plus or minus 3.7 mV and an input resistance of 10.2 plus or minus 3.5 (the unit is partly lost in scanning)
  • Chrysotile without serum: a significant decline in both membrane potential and input resistance, greatest at three hours
  • Chrysotile with serum (conditioned medium): an initial marked rise in membrane potential, a steady fall after 23 hours, and by 48 hours 60% of the cells tested were dead
  • Crocidolite without serum: no statistically significant changes in membrane potential or input resistance
  • Crocidolite with serum: marked oscillation in both measures over the first six hours, then values similar to controls for the rest of the experiment
  • Amosite without serum: marked hyperpolarization (a rise in membrane potential), greatest one hour after addition, then a gradual return to control values
  • Amosite with serum (conditioned medium): an initial increase, values equal to controls from five hours for the next 25 hours, then a steep decline, so that by 47 hours 80% of the cells tested were dead
  • Waves of hyperpolarizing activity, 0.5 to 1.0 mV in control cells, increased in amplitude (7 to 12.5 mV) and in frequency with any of the asbestos samples
  • Amosite was more toxic to the cells than in previous studies. The authors suggested this may have been due to a relatively high ratio used in these experiments.
• The authors' conclusion: The authors concluded that different fibres can cause different electrical changes in the cells, both early on and when cell damage appears, suggesting that different mechanisms of cytotoxicity are involved

Topics

Medical terms in this study, explained in our Lexicon: Macrophage, UICC, Chrysotile, Crocidolite, Amosite.

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