ABSTRACT
BACKGROUND AND OBJECTIVES: Social awareness of the narcotic effects of industrial adhesive vapors have been aroused by some teens who are reported to inhale these vapors to get the narcotic effects. When inhaled, the toxic effects of these chemicals are concentrated to the field of central nervous system, and the excretion system of metabolites like the liver and kidney. The effects of industrial adhesive vapors on the respiratory epithelium are unclear so far. MATERIALS AND METHOD: This was designed to study the morphological changes after exposure of the chemicals on the nasal mucosa in mice. Young healthy mice were exposed to industrial adhesive vapor (mixtures of acetone 5212+/-1268 ppm, c-hexane 3757+/-711 ppm, methyl cyclopentane 1820+/-375 ppm, n-hexane 139+/-30 ppm, toluene 0.9+/-1.4 ppm) for 20 min, once daily for 3 days, 5 days, 7 days, and 14 days. After adhesive vapor exposure, mice respiratory mucosa were excised, fixed in 4% paraformaldehyde for immuno-histochemistry and in 2.5% glutaraldehyde -1.5% paraformaldehyde for transmission electron microscopy and in 2.5% glutaraldehyde for scanning electron microscopy. Fixed tissues were processed for immunohistochemistry and for electron microscopy. RESULTS: Cellular degeneration and necrosis were seen on exposure day 3 and 5 which included erosion or ulceration of epithelium, exfoliation of cell, deciliation, shrinkage of goblet cells etc. The architecture of ciliated columnar cells and goblet cells were regenerated on day 7. Among the ciliated cells, most of the cells were replaced by cuboid ciliated cells. And the secretory pattern of the goblet cells were also changed from the merocrine to apocrine type at same days of exposure. On the other hand, the PCNA immunochemical study revealed that positive cells were increased on day 5. CONCLUSION: These results suggest that the nasal mucosa of mice can be damaged to some extent by daily regular exposure of industrial adhesive vapor. However, it could have a potency of regeneration to cuboidal cells, which are thought to change into more resistant cells in order to adapt to repetitive external stimuli.
Subject(s)
Adolescent , Animals , Humans , Mice , Acetone , Adhesives , Central Nervous System , Cyclopentanes , Epithelium , Glutaral , Goblet Cells , Hand , Immunohistochemistry , Inhalation , Kidney , Liver , Microscopy, Electron , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Narcotics , Nasal Mucosa , Necrosis , Proliferating Cell Nuclear Antigen , Regeneration , Respiratory Mucosa , Toluene , UlcerABSTRACT
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.