Stimulation of oxidant production in alveolar macrophages by pollutant and latex particles

Our plain-English summary of Stimulation of oxidant production in alveolar macrophages by pollutant and latex particles, by G.E. Hatch, D.E. Gardner, D.B. Menzel (Environmental Research, 1980).

The study

• Authors: G.E. Hatch, D.E. Gardner, D.B. Menzel
• Journal: Environmental Research
• Published: 1980;23(1):121-36
• Cited by: 70 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Air pollutant dusts as well as chemically defined particles were examined for their activating effect on oxidant production (O2- and H2O2) in guinea pig alveolar macrophages (AM). Oxidant production was measured as chemiluminescence of albumin-bound luminol. All particles examined stimulated the AM in a dose-dependent manner to different maximal levels of oxidant production. Amphibole asbestos samples were the most active of all agents studied. Various immune reactants as well as silica, metal-oxide-coated fly ash, polymethyl methacrylate beads, and chrysotile asbestos had intermediate activity, while fugitive dusts, polybead carboxylate microspheres, glass and latex beads, uncoated fly ash, and fiberglass had the lowest activity. In addition to direct stimulatory action on AM, particles also lowered the subsequent responsiveness of the cells to the bacterial peptide stimulant, N-formylmethionyl phenylalanine. This effect was only partially due to the cytotoxicity of the particles. While some relationship appeared to exist between stimulatory activity and cytotoxicity of the particles, the exact role of O2- in mediating cytotoxic effects is still open to question. Oxidant production in AM is a parameter which may be important in determining the pathological effects of particles as well as of materials adsorbed to their surfaces.

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

In plain English

This was a laboratory study of cells, not of people. The authors took alveolar macrophages, immune cells that clear particles from the lung's air sacs, from male guinea pigs. They measured oxidant production indirectly, as light given off by the chemical luminol, in arbitrary units. The particles included standard UICC samples of amosite, anthophyllite, crocidolite, Rhodesian chrysotile A and Canadian chrysotile B asbestos. They also included fly ash, road and rock dust, fiberglass insulation, silica, and plastic and glass beads. All particles increased oxidant production with dose, except that the largest latex beads (7.6 micrometres) showed only a slight upward trend. The three amphibole types (crocidolite, anthophyllite and amosite) were the most active of all agents tested. The chrysotiles were about one-fourth as active, and fiberglass had almost no effect. An enzyme that removes superoxide did not protect cells exposed to anthophyllite asbestos or several other particles from losing viability. The authors noted that metal ions in amphibole samples might artificially raise the readings. They concluded that oxidant production by these cells may be important in determining the harmful effects of particles.

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 alveolar macrophage cells taken from guinea pigs; oxidant production was measured indirectly as light from luminol (chemiluminescence), in arbitrary units of volts per million cells
• Who was studied: alveolar macrophages washed out of the lungs of male Hartley-strain guinea pigs (650-800 g). The comparison table gives the number of animals for each particle type, for example 11 animals for crocidolite and 7 for chrysotile A.
• Exposure: UICC standard amosite, anthophyllite, crocidolite, Rhodesian chrysotile A and Canadian chrysotile B asbestos, added to cells in suspension. These were compared with fly ash (uncoated and coated with lead, nickel or manganese oxides), road dust, rock dust, fiberglass insulation, silica, zymosan, and latex, glass and plastic microspheres.
• Main results:
  • All sizes of latex beads caused a dose-dependent increase in oxidant production, except the largest (7.6 micrometre) beads, which showed only a slight upward trend
  • The three amphibole asbestos types (crocidolite, anthophyllite, amosite) were extremely active in stimulating oxidant production by the macrophages; chrysotiles A and B were about one-fourth as active
  • Crocidolite (and other amphibole samples) gave the highest maximal oxidant production of all particles tested. In the comparison table crocidolite averaged 4.68 plus or minus 1.25 (11 animals), against a basal level of 0.18 plus or minus 0.13 (16 animals), in volts per million cells.
  • Chrysotile was about one-half as active as fumed silica
  • Fiberglass insulation, the only other fibrous material studied, had almost no stimulatory activity on the macrophages
  • Maximum responses to asbestos were often reached at a low concentration of 0.4 mg/ml
  • Lead and nickel oxide coatings on fly ash increased maximum oxidant production as much as sixfold over uncoated fly ash
  • Liquid filtered from the amosite suspension (not the fibers themselves) increased the cells' later response to a bacterial peptide stimulant by 80% over control. Liquid from nickel oxide-coated and manganese oxide-coated fly ash raised it by 230% and 51%.
  • Superoxide dismutase, an enzyme that removes superoxide, did not protect macrophages exposed to latex, fly ash, lead oxide fly ash, anthophyllite asbestos or silicic acid
• The authors' conclusion: The authors concluded that oxidant production in alveolar macrophages may be important in determining the harmful (pathological) effects of particles and of materials on their surfaces. Their efforts to show that oxidant production causes the particles' toxic effects on the cells were unsuccessful.
• Limitations the authors state:
  • Responses varied considerably between cells from different animals, although the ranking of particles stayed consistent
  • Metal ions possibly present in larger amounts in amphibole asbestos might have produced an artificially high oxidant reading by acting directly on the luminol
  • Accurate measurement of cell viability was technically difficult in cells loaded with particles

Topics

Medical terms in this study, explained in our Lexicon: Alveolar Macrophage, Amphibole Asbestos, Chrysotile.

Related studies

• Differences between particulate and peptide stimuli on activation of oxidant production in alveolar macrophages — G.E. Hatch, A. Spock, et al. (1980)
• Response of bovine alveolar macrophages in vitro to welding fume particles — L.R. White, A.B. Marthinsen, et al. (1983)
• Interleukin 1 production and accessory cell function of rat alveolar macrophages exposed to mineral dust particles — Y. Oghiso, Y. Kubota (1987)
• Morphologic characterization of alveolar macrophages from subjects with occupational exposure to inorganic particles — T. Takemura, W.N. Rom, et al. (1989)
• Alveolar macrophage stimulation of lung fibroblast growth in asbestos-induced pulmonary fibrosis — I. Lemaire, H. Beaudoin, et al. (1986)
• Relative effects of asbestos and wollastonite on alveolar macrophages — W.H. Pailes, D.J. Judy, et al. (1984)

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