Glutathione release by pulmonary alveolar macrophages in response to particles in vitro

Our plain-English summary of Glutathione release by pulmonary alveolar macrophages in response to particles in vitro, by D.S. Boehme, K.R. Maples, R.F. Henderson (Toxicology Letters, 1992).

The study

• Authors: D.S. Boehme, K.R. Maples, R.F. Henderson
• Journal: Toxicology Letters
• Published: 1992;60(1):53-60
• Cited by: 29 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

We studied whether cultured rat pulmonary alveolar macrophages (PAM) could release glutathione (GSH) in response to latex beads, quartz, and crocidolite asbestos. PAM were exposed for 2 h to 0-100 micrograms of particles per 1 x 10(6) cells. Both quartz and asbestos produced concentration-dependent increases (up to 8-10-fold) in the amount of GSH recovered in the medium and decreases in the cellular GSH levels. In contrast, latex beads did not produce any changes in GSH levels. We also measured lactate dehydrogenase (LDH) levels as an index of toxicity. Only quartz and asbestos were able to produce increases in LDH levels in the medium. The release of GSH occurred at particle concentrations that did not cause release of LDH. Our results indicated that, in vitro, PAM release GSH in response to toxic particles.

In plain English

This was a laboratory (in vitro) experiment using rat lung cells, not a study of people. The authors collected pulmonary alveolar macrophages, cells that clear inhaled particles, by washing the lungs of female F344/N rats. They exposed the cells for 2 hours to latex beads, quartz, or crocidolite asbestos at 20, 50 or 100 micrograms per million cells, and measured glutathione (GSH), an antioxidant, in the cells and the surrounding fluid. Quartz and asbestos produced concentration-dependent increases in GSH in the fluid, on the order of 8- to 10-fold at the highest concentration, while GSH inside the cells fell. Latex beads produced no significant changes. Lactate dehydrogenase (LDH), a sign of cell damage, rose significantly with quartz only at the highest concentration (2-fold), and nearly 3-fold with asbestos at the highest concentration. Latex beads caused no significant LDH rise. The authors concluded that the cells release GSH in response to toxic particles, reflecting particle concentration and toxicity. They said it was unclear whether this was a specific response or a more sensitive sign of cell damage than LDH.

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 rat lung macrophages exposed to particles for 2 hours
• Who was studied: Pulmonary alveolar macrophages collected by lung lavage from pathogen-free female F344/N rats aged 12-24 weeks (number of rats not stated; figures report 3 trials)
• Exposure: Latex beads (relatively non-toxic comparison particle), quartz, and crocidolite asbestos at 20, 50 or 100 micrograms of particle per million cells for 2 hours
• Main results:
  • Quartz and asbestos produced concentration-dependent increases in GSH in the medium, on the order of 8- to 10-fold at the highest concentration
  • Cells exposed to quartz and asbestos showed a concentration-dependent loss of GSH; latex beads produced no significant changes in GSH (data not shown)
  • Latex beads produced no significant changes in GSH levels
  • LDH in the medium after quartz (silica) exposure was significantly increased only at the highest concentration, 2-fold over control
  • Asbestos produced a nearly 3-fold increase in LDH in the medium at the highest concentration; latex beads produced no significant LDH increase
  • Oxidized glutathione (GSSG) in medium and cells showed no dose-response for any particle
  • The authors reported that GSH release occurred at particle concentrations that did not cause LDH release
• The authors' conclusion: The authors concluded that rat alveolar macrophages release GSH in response to toxic particles, and that the release reflected the concentration and toxicity of the particle
• Limitations the authors state:
  • The authors stated it was not clear whether GSH release was a specific response to toxic particles or a more sensitive marker of cell damage than LDH release

Topics

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

Medical terms in this study, explained in our Lexicon: Glutathione (GSH), Alveolar Macrophage, Crocidolite, Lactate Dehydrogenase (LDH).

Related studies

• Cytokine and free radical responses of alveolar macrophages in vitro to asbestos fibres — L.C. Mongan, T. Jones, et al. (2000)
• Refractory ceramic fibers activate alveolar macrophage eicosanoid and cytokine release — G.D. Leikauf, S.P. Fink, et al. (1995)
• Human alveolar macrophage cytokine release in response to in vitro and in vivo asbestos exposure — R.C. Perkins, R.K. Scheule, et al. (1993)
• Cytotoxic effects of quartz and chrysotile asbestos: in vitro interspecies comparison with alveolar macrophages — J. Schimmelpfeng, A. Seidel (1991)
• Response of bovine alveolar macrophages in vitro to welding fume particles — L.R. White, A.B. Marthinsen, et al. (1983)
• Iron and reactive oxygen species in the asbestos-induced tumor necrosis factor-alpha response from alveolar macrophages — P.P. Simeonova, M.I. Luster (1995)

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