Toluene diisocyanate exposure induces laryngo-tracheal eosinophilia, which can be ameliorated by supplementation with antioxidant vitamins in guinea pigs.
OBJECTIVE
Toluene diisocyanate (TDI)-induced asthma is a common cause of occupational lung disease. In addition, a sore throat is one of the complaints of TDI-exposed workers. The aim of the present study was to determine whether TDI exposure induces laryngeal and/or tracheal lesions in experimental animals.


METHODS
Guinea pigs underwent naris application of TDI three times, and their respiratory tracts were then examined using light and electron microscopy. Some animals simultaneously received vitamins C and E. which function as antioxidant agents.


RESULTS
When TDI-treated animals showed the clinical sign of labored breathing, many eosinophils had appeared in the lamina propria and mucosa of both the larynx and trachea, which finally infiltrated the tract lumen through the ruptured epithelium. Laryngo-tracheal inflammation was more severe than that observed in the lungs. However, supplementation with antioxidant vitamins in TDI-treated animals ameliorated the respiratory eosinophilia.


CONCLUSIONS
Naris application of TDI induced laryngotracheitis. which was significantly suppressed by the antioxidant vitamins, This implies a preventive effect of the vitamins on this occupational disease.
Gu
He
H
Department of Anatomy, Kagawa Medical University, Kagawa, Japan.
Itoh
Masahiro
M
Matsuyama
Nagahisa
N
Hayashi
Shogo
S
Iimura
Akira
A
Nakamura
Yoichi
Y
Miki
Takanori
T
Takeuchi
Yoshiki
Y
D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use*; D001205:Ascorbic Acid / Q000627:therapeutic use*; D004195:Disease Models, Animal; D006168:Guinea Pigs; D007830:Larynx / Q000187:drug effects / Q000648:ultrastructure; D008297:Male; D011657:Pulmonary Eosinophilia / Q000139:chemically induced* / Q000473:pathology / Q000517:prevention & control*; D014051:Toluene 2,4-Diisocyanate / Q000633:toxicity*; D014132:Trachea / Q000187:drug effects / Q000648:ultrastructure; D024502:alpha-Tocopherol / Q000627:therapeutic use*
D000975:Antioxidants; D014051:Toluene 2,4-Diisocyanate; D024502:alpha-Tocopherol; D001205:Ascorbic Acid