ABSTRACT
The experiments of this study was performed to investigate the effects of sulfur dioxide on the changes of glycoconjugates of respiratory system of the rat. Sprague -Dawley male rats weighing about 200 ~250g were divided into a control group and SO2 exposed groups. Again SO2 exposed groups were divided into 10 ppm, 25 ppm, 50 ppm, 100 ppm and 200 ppm subgroups according to concentrations of SO2 and each SO2 exposed groups were divided into 1, 3 and 6 hours groups. For the histological changes, H -E(hematoxylin -eosin) and PAS(periodic acid Schiff) staining were used and to investigate the change of sugar residues of glycoconjugates, biotinylated lectins(DBA, SBA, PNA, BSL -1, sWGA, UEA -1, LCA and Con A) were applied. Generally, the effects of SO2 on the rat nasal respiratory region were more serious at the high concentrations. Moreover, as the exposed time was longer even at the low concentrations, the effects of SO2 were similar to those of high concentration. Compared with all SO2 concentrations, the longer exposed time was, the more serious the effects of SO2 were. In the SO2 exposed groups the binding of PNA, RCA -1 and UEA -1 of cilia in the nasal septal respiratory epithelium tended to increase in the 10 ppm and 25 ppm SO2 exposed groups but it tended to decrease in the 100 ppm and 200 ppm SO2 exposed groups. In the cytoplasm of columnar cells of nasal septal respiratory epithelium, Con A binding increased in all the SO2 exposed groups. In the goblet cells DBA, SBA, PNA, RCA -1 and UEA -1 binding increased remarkably in the 50 ppm SO2 exposed groups but it decreased largely or disappeared in the 100 ppm and 200 ppm SO2 exposed groups. The binding of SBA, PNA, BSL -1, UEA -1 and Con A in the intraepithelial mucous cells which were not detected in the control group, increased in the 25 ppm and 50 ppm SO2 exposed groups while it tended to decrease in the 100 ppm and 200 ppm SO2 exposed groups. The binding of sWGA increased according to the concentrations of SO2 were higher and exposed times were longer. In the superior nasal septal gland, the binding of PNA increased in the 50 ppm and 100 ppm SO2 exposed groups and that of Con A increased in the 25 ppm and 50 ppm SO2 exposed groups. In the inferior nasal septal gland, except for LCA, the binding of the other lectins increased remarkably in the 25 ppm and 50 ppm SO2 exposed groups but it tended to decrease in the 100 ppm and 200 ppm SO2 groups. In the mucous duct cells, the reaction of PNA and RCA -1 increased compared with that of the control group. And the reaction of BSL -1 and UEA -1 increased in the lower concentrations of 50 ppm SO2 exposed group but it decreased in the 100 ppm and 200 ppm SO2 exposed groups. The binding of Con A increased in the 25 ppm and 50 ppm SO2 exposed groups. Consequently, from the results above mentioned that SO2 affected serious changes on glycoconjugates metabolism in the nasal cavity.