Effect of lead on the structure of the tongue of adult male albino rat and the possible protective role of selenium, light and scanning electron microscopic study

Lead poisoning persists as a major public health problem throughout the world, despite efforts to reduce lead hazards in the environment. This study was done to investigate the effect of lead on the structure of the tongue and to evaluate the possible protective role of selenium against this effect. Twenty adult male albino rats were used in this study. They were divided into four groups; five animals each. Group I: control group. Group II: animals received selenium orally in a dose of 00.35mg/kg body weight/day for eight weeks. Group III: animals received oral doses of lead acetate [20mg/kg body weight/day] for eight weeks. Group IV: included animals that received both lead acetate and selenium concomitantly in the same previously mentioned doses and duration. At the end of the experiment, tongue specimens were taken and prepared for light and scanning electron microscopic study. The results of the study showed that lead caused multiple histological changes on the structure of the tongue. Papillae appeared deformed in shape and reduced in size. They were irregularly arranged with altered direction. The thickness of the surface epithelium and the keratin layer was reduced. The skeletal muscle fibers were degenerated. Congestion and mononuclear cellular infiltration were also noticed. The collagen content inbetween the skeletal muscle fibers was increased. In addition, there were attenuation, beading and interrupted course of the nerve fibers. These histological changes were markedly improved when selenium was given concomitantly with lead