1058 Int. J. Morphol., 29(3):1058-1061, 2011. Ultrastructural Changes in the Kidney Cortex of Rats Treated with Lead Acetate Cambios Ultraestructurales en la Corteza Renal de Ratas Tratadas con Acetato de Plomo Deveci, E.; Söker, S.; Baran, Ö.; Tunik, S.; Ayaz, E. & Deveci, S. DEVECI, E.; SÖKER, S.; BARAN, Ö.; TUNIK, S.; AYAZ, E. & DEVECI, S¸ Ultrastructural changes in the kidney cortex of rats treated with lead acetate. Int. J. Morphol., 29(3):1058-1061, 2011. SUMMARY: The purpose of this study was to investigate the ultrastructural effects of lead on the kidney cortex of rats. Wistar Albino rats (180-200g body weight) were divided into a controlled and lead acetate-exposed group. Rats received lead acetate at 500 ppm in their drinking water for 60 days. Both groups were fed with the same standard food, but lead acetate was added to the drinking water. During the experimental period, blood samples were taken from the abdominal aorta of the anesthetised animals. At the end of exposure, body weight and blood lead levels were measured. The kidney tissue samples were prepared and analyzed by light and transmission electron microscopy. Cortical renal tubules show various degenerative changes with focal tubular necrosis invaded by inflammatory cells. The ultrastructural alterations found in lead acetate-treated rats were a diminution in the amount of filtration slits, increased fusion of foot processes in epithelial cells of the glomeruli, increase of lysosomal structures and pinocytic vesicles as well as large mitochondria in proximal tubule cells. KEY WORDS: Lead acetate; Kidney cortex; Ultrastructural changes. INTRODUCTION Lead (Pb) is a toxic metal that induces a broad range of physiological, biochemical and neurological dysfunctions in humans (Deveci, 2006). Lead is a widely distributed and ubiquitous environmental pollutant, shown to be, representing a high toxicological and ecotoxicological risk. Many animal studies have shown that lead is capable of causing oxidative stress in the kidney, liver, and brain (Ercal et al., 1996; Patra et al., 2001). The absorbed Pb is conjugated in the liver and passed to the kidney, where a small quantity is excreted in urine and the rest accumulates in various body organs, affecting and affects many biological activities at the molecular, cellular and intercellular levels, which may result in morphological alterations that can remain even after Pb levels have fallen (Jarrar, 2003; Sidhu & Nehru, 2004; Taib et al., 2004; Flora et al., 2006). The kidney is a sensitive target organ for lead exposure. The purpose of this study is to investigate the ultrastructural effect of lead acetate in the kidney cortex. MATERIAL AND METHOD Animals. Wistar rats (9 weeks old, 180-200 g body weight) used in these trials were divided into two groups of 30 animals each (control group and experimental group). Animals of the experimental group were given drinking water containing 500 ppm lead acetate for a period of 2 months. The rats were obtained from the Department of Medical Science Application and Research Centre of Dicle University. All the animals were individually housed in stainless steel cages at room temparature. The animals had free access to standard laboratory rat pellet and water. The animals were sacrificed by decapitation under ether anesthesia, and kidney tissue were quickly removed. Histopathological analysis. For sample preparation under light microscopy after fixation of tissues by formaldehyde 10% solution, they were directly dehydrated in a graded serious of ethanol and embedded in paraffin. Thin sections, 5-6 micrometres, were cut by using a microtome and stained Department of Histology and Embryology, Medical Faculty, Dicle University, Diyarbakir, Turkey.