Relative effects of asbestos and wollastonite on alveolar macrophages

Abstract

Rabbit alveolar macrophages were exposed in culture to chrysotile asbestos, wollastonite, or latex, and the effects on various biochemical and physiological parameters related to cellular viability and fibrogenicity were determined. Exposure of alveolar macrophages to asbestos, wollastonite, or latex for 3 d has no effect on oxygen consumption or cellular volume. However, treatment of alveolar macrophages with as little as 25 micrograms asbestos/ml for 1 d increases lysosomal enzyme release and decreases membrane integrity, i.e., decreases trypan blue exclusion and increases leakage of cytosolic enzymes. In contrast, exposure of alveolar macrophages to wollastonite or latex at 250 micrograms/ml does not induce lysosomal enzyme release or alter membrane integrity even after 3 d of exposure in culture. These data suggest that chrysotile asbestos damages rabbit alveolar macrophages, while wollastonite, a potential substitute for asbestos, is far less cytotoxic.

Vitronectin enhances internalization of crocidolite asbestos by rabbit pleural mesothelial cells via the integrin alpha v beta 5.

“…By counts under phasecontrast microscopy, there were 200 x 106 fibers/g. Wollastonite, a relatively nonpathogenic calcium silicate fiber in both in vitro (18) and in vivo (19) studies, was used as a control fiber. The preparation of wollastonite used was Nyglos I (or Rimglos), milled to a geometry mimicking that of crocidolite asbestos (mean length 12 tm, range 2-80 tm, mean width 2 Am) (NYCO Minerals, Willsboro, NY).…”

In Vitro Effects of Large and Small Glass Fibers on Rat Alveolar Macrophages

“…However, chronic inhalation of fiberglass in rats resulted in neither pulmonary fibrosis nor cancer (Hesterberg et al, 1993). In contrast, an in vitro assay system has been able to verify epidemiological data suggesting that wollastonite is less pathogenic than asbestos (Pailes et al, 1984).…”

“…These agents may directly damage the lung parenchyma, as well as recruit and activate other cells (e.g., neutrophils and fibroblasts) that are important in alveolitis and the development of fibrosis. In our laboratory, alveolar macrophage cultures have proven to be an accurate system to evaluate the toxicity of chrysotile asbestos and wollastonite (Pailes et al, 1984); chrysotile was determined to be toxic, while wollastonite was deemed far less toxic and latex beads were found to be nontoxic. These in vitro results correlate with the epidemiological finding of Shasby et al (1979) that wollastonite is nontoxic to exposed workers.…”

“…The incubation of alveolar macrophages with fibers has been shown to be an accurate system to assess the toxicity of chrysotile asbestos and wollastonite (Pailes et al, 1984). The comparison of crocidolite asbestos and riebeckite, its nonasbestiform polymorph, in an in vitro system demonstrated that physical characteristics of particles may not be the sole determinant of toxic potential (Castranova et al,366 V. CASTRANOVA ET AL.…”

A Review of the Toxicology and Epidemiology of Wollastonite

“…Generally speaking, these studies indicated that wollastonite caused cellular level effects, but these were less than those observed with various types of asbestos. For example, Pailes et al (1984) exposed cultures of rabbit alveolar macrophages to chrysotile, wollastonite (NYCO Minerals, 98% ≤8µm length), and latex beads at concentrations ranging from 50 to 250 µg/ml. The authors found that chrysotile was cytotoxic whereas wollastonite was far less cytotoxic.…”