Effect of erionite on the pleural mesothelium of the Fischer 344 rat.

Journal Article (Journal Article)

OBJECTIVE: This study sought to assess the fibrogenic and carcinogenic potential of erionite (a fibrous zeolite) on the pleural mesothelium of the Fischer 344 rat (n = 24). DESIGN: The study was designed to examine rat pleural mesothelial changes by three independent observers at timed intervals, ranging from 1 to 480 days postinoculation using erionite from the Pine Valley, Nevada (USA) area. The mean length and width of the erionite fibers were 2.29 and 0.48 microns, respectively. Only microscopic observations made by majority (2/3) or unanimity (3/3) were accepted for final diagnosis. RESULTS: Pleural and lung tissue were available for examination in 21 of the 24 rats. Fibrosis, chronic inflammation, and foreign body reaction occurred in 6 of 21 rats. Mesothelial hyperplasia and dysplasia occurred in 9 and 3 of the 21 rats, respectively. A single mesothelioma was identified at 434 days in a rat that had gross nodular pleural lesions. CONCLUSIONS: The findings reported herein confirm the strong fibrogenic potential of erionite but are at variance with previous studies reporting much higher yields of mesothelioma. The reasons for the low yield of mesothelioma in this study are not known, but may be related to the study design, the strict criteria used for histopathologic diagnosis, and/or possible differences in erionite physicochemical properties, associated with its geographic distribution, most previous animal studies having used erionite from the Rome, Oregon (USA) area.

Full Text

Duke Authors

Cited Authors

  • Fraire, AE; Greenberg, SD; Spjut, HJ; Dodson, RF; Williams, G; Lach-Pasko, E; Roggli, VL

Published Date

  • May 1997

Published In

Volume / Issue

  • 111 / 5

Start / End Page

  • 1375 - 1380

PubMed ID

  • 9149597

International Standard Serial Number (ISSN)

  • 0012-3692

Digital Object Identifier (DOI)

  • 10.1378/chest.111.5.1375


  • eng

Conference Location

  • United States