Morphological Changes of the Olfactory Mucosa in Mice Exposed to Industrial Bond Vapor

Ahn, Hee Young; Kang, Ki Hoon; Han, Dong Yul; Kim, Dong Wook; Lee, Byung Don; Oh, Cheon Hwan; Chang, Hyuck Soon

Abstract

BACKGROUND AND OBJECTIVES: Recently, accidents have been reported of young adults who inhale industrial bond vapor. Acquiring industrial bond is easy for young adults, and glue sniffing has thus become a serious social problem. However, there have been few reports concerning the changes in the olfactory epithelium after exposure of industrial bond vapor. The aim of this study is to describe the morphological changes of the olfactory mucosa after being exposed to industrial bond vapor, using HE, AB, AB-PAS stains, immunohistochemistry and the electron microscopy. MATERIALS AND METHOD: Healthy ICR mice were exposed to industrial bond vapor (acetone 5212+/-1268 ppm, c-hexane 3757+/-711 ppm, methylcyclopentane 1820+/-375 ppm, n-hexane 139+/-30 ppm and toluene 0.9+/-1.4 ppm). The vapor was given to each animal with duration of 20 min/day for 3 days, 5 days, 7 days or 14 days in a specially designed box for this study. After exposure to industrial bond vapor, mice olfactory mucosae were excised and prepared for HE, AB, AB-PAS stains, immunohistochemistry and electron microscopy.
RESULTS
Loss of cells and disarrangements of olfactory epithelium were prominent on the third day of exposure and the epithelium recovered to the normal state after the day 7 in the HE stain. And there were also definite ultrastructural changes in the epithelium : loss of microvilli in supporting cells, exposure of olfactory vesicles to the luminal surface and apoptotic bodies in electron microscopic study. Study with the AB and AB-PAS stains demonstrated an evidence of decreased mucin secretion on the day 3 and the content of mucin was normalized after the day 7. In the PCNA study, cells were unable to proliferate until day 3. The proliferation potential were increased (4 fold) on day 5 and returned to normal on day 14.
CONCLUSION
This result indicated that industrial bond vapor can damage the olfactory epithelium of mice which can recover rapidly. Apoptosis and active proliferation could be the factors that are involved in the recovery of the epithelium that is open to regular industrial bond vapor exposure on daily basis.