Effects of metals cadmium and chromium alone and in combination on the liver and kidney tissue of male Spraque‐Dawley rats: An ultrastructural and electron‐energy‐loss spectroscopy investigation

Abstract

Heavy metal pollution has increased in the last decades. Water sources are contaminated and human exposure is often long term exposure to variable amounts of different metals. In this study, male Sprague-Dawley rats were exposed via oral gavage for 28 days to cadmium (Cd) and chromium (Cr), alone and in combination at concentrations 1000 times the human World Health Organization's acceptable water limits. Rat equivalent dosages were used. Blood markers of liver and kidney function were measured, changes to cellular morphology was determined with transmission electron microscopy and the intracellular metal localisation was determined with the electron energy-loss spectroscopy and energy filtered transmission electron microscopy analysis. Both Cd and Cr caused changes to the nuclear and mitochondrial membranes and irregular chromatin condensation of hepatocytes. Cr exposure caused dilation of the rough endoplasmic reticulum (rER). The combination caused nuclear and mitochondrial membrane damage as well as irregular chromatin condensation. In the kidney tissue, Cd caused irregular chromatin condensation in the cells of the proximal convoluted tubule (PCT). Cr caused changes to the outer nuclear and mitochondrial membrane and chromatin structure. The combination group caused membrane damage, irregular chromatin condensation and rER changes in the PCT. All the metal groups showed damage to the endothelial cells and pedicles, but not to the mesangial cells. Cd and Cr bio-accumulation was observed in the nucleus, mitochondria and rER of the liver and kidney and therefore are responsible for the cellular observed damage that can cause functional changes to the tissues and organs.

Protective Effect of Lactoferrin against Chromium Induced Adverse Renal Changes in Rats: Oxidative Stress Theory

“…This was in line with proven literature evidence of alteration of renal functions caused by Cr. The rise in these parameters was due to loss of functional integrity in the kidney and renal tubule distortion as a consequence of Cr administration (Venter et al, 2017). Many studies were in line with our findings and clarified that Cr-induced renal dysfunction could be due to Cr renal tubular damage and cell debris obstruction (Sahu et al, 2014;Hegazy et al, 2016).…”

Nickel oxide nanoparticles induce genotoxicity and cellular alterations in the ground beetleBlaps polycresta(Coleoptera: Tenebrionidae)

“…Various ultrastructure anomalies in the testicular cells were observed in the NiO-NPs-treated group, including anatomical alterations in the nucleus and cytoplasm in almost all the spermatogenic stages. These anomalies are a consequence of DNA and protein damage, as well as impairment of membranes due to the action of a xenobiotic (Bertin and Averbeck, 2006;Venter et al, 2017). Metals can change the structure of membranous organelles such as the mitochondria and endoplasmic reticulum, as well as plasma and nuclear membranes nu binding to membranes and DNA-associated proteins (Venter et al, 2017).…”

Flavocoxid, a Natural Antioxidant, Protects Mouse Kidney from Cadmium‐Induced Toxicity

“…As to the cells of the proximal tubule, in CdCl 2 -challenged mouse lysosomes and myelin bodies, distorted or ring-shaped mitochondria, cytoplasmic vacuolization or cytolysis [ 13 ], decreased, irregular microvilli [ 16 ], fragmented and short basolateral invaginations [ 15 ], and condensed chromatin [ 17 ] have been described.…”

“…In fact, damaged liver cells release a Cd-metallothionein (MT) complex which is filtered from the glomerulus and then endocytosed by the cells of the proximal tubule, where it is degraded by lysosomes: in this way, free Cd is released in the tubules [ 10 ], where 99% of the filtered Cd is reabsorbed [ 11 ], resulting in accumulation and consequent nephrotoxicity. In particular, it was demonstrated that the target sites of Cd are the proximal tubules [ 12 ]; in these structures, lesions of the brush border and fragmentation of the epithelial cells with the granular cytoplasm were observed [ 13 – 17 ]. However, Cd-induced structural damages of the glomeruli [ 18 ], consisting in increased mesangial matrix, glomerular swelling, and increased urinary space, were also demonstrated [ 19 ].…”