Cadmium and iron accumulation in rat lens after cigarette smoke exposure and the effect of vitamin E (alpha-tocopherol) treatment

Purpose. Cadmium accumulation in the lens has been implicated in cataractog enesis of chronic smokers. This study was planned to evaluate whether or no t in vivo cigarette smoke exposure causes cadmium accumulation in rat lens, and possible protective effect and mechanism of alpha-tocopherol (vitamin E) treatment on cataractogenesis. Methods. 28 male Wistar rats were randomly divided into four equal groups. Group 3 and 4 rats were exposed to cigarette smoke over ninety consecutive days, and Group 1 and 2 rats were treated in a similar fashion but exposed only to room air. Additionally, vitamin E was given to Group 2 and 4 rats. Results. Significantly higher iron levels were observed in the lenses of Gr oup 3 rats compared to other groups. With respect to cadmium, Group 3 and 4 rats had significantly higher levels compared to Group 1 and 2 rats. Altho ugh vitamin E treatment prevented iron accumulation in Group 4 rats, it had no effect on cadmium concentrations. Distinct histopathological changes ob served in Group 3 rats were not present in Group 4 rats. Conclusion. Our study demonstrates that in vivo cigarette smoke exposure ca uses accumulation of cadmium in rat lens and IM vitamin E treatment does no t affect this accumulation. The protective effect of vitamin E treatment on smoke exposed rat lens seems to be mediated by blockage of iron accumulati on in the lens.