Effect of Cadmium on the Renal Cortex of Adult Albino Rat and the Possible Protective Role of α- lipoic Acid

Background: Cadmium (Cd) toxicity is related to the tissue oxidative stress due to reactive oxygen species. Alpha-lipoic acid (α-LA) has been identified as an ideal antioxidant capable of regenerating endogenous antioxidants in the body. Aim of the Work: This study was conducted to elucidate the effect of administration of cadmium on the structure of the renal cortex of the albino rat and to find out the possible protective role of concomitant administration of α–LA. Material and Methods: This study was carried out on 60 male adult albino rats divided into four groups. Group I (normal control group), 10 rats. Group II (sham control group), 30 rats, they were divided into 3 equal subgroups IIa, IIb & IIc received saline, saline with NaOH solution and α-LA respectively. Group III, 10 rats, received Cd intraperitoneally. Group IV, 10 rats, received Cd and α-LA intraperitoneally. The animals of all groups were sacrificed after one and four weeks of the experiment and renal cortical specimens were subjected to light and electron microscopic studies. Results: After Cd administration, there were many changes in the renal cortex which were in line with the period of administration. The glomeruli appeared with congested blood capillaries, shrunken or severely degenerated. The glomerular capillary basement membrane was thickened and degenerated or disrupted in many areas. The major processes of some podocytes were degenerated with loss of minor processes. The Bowman's space was obliterated, widened, or contained hemorrhage or tissue debris. The proximal convoluted tubules (PCT) appeared with widened lumen with casts or debris. Some cells of the PCT showed disrupted brush border with few or absent microvilli. Other cells were of degenerated or vacuolated cytoplasm with few mitochondria or absence of organelles. The nuclei became pyknotic in some cells. The distal convoluted tubules (DCT) were less affected. Few of them showed tissue debris, casts or desquamated cells in their lumen. The cytoplasm of some cells of DCT was vacuolated. Concomitant administration of α–LA with Cd greatly minimized these changes. Conclusions: Cd administration resulted in marked degeneration in the renal cortex. These effects were in line with the period of exposure and that α –LA had a protective role against Cd induced toxicity