Nephron ultrastructural alterations induced by zinc oxide nanoparticles: an electron microscopic study

Due to their unique properties, zinc oxide nanoparticles (ZnO NPs) are invested in many industries, commercial products, and nanomedicine with potential risk for human health and the environment. The present study aims to focus on alterations that might be induced by ZnO NPs in the nephron ultrastructure. Male Wister Albino rats were subjected to ZnO NPs at a daily dose of 2 mg/kg for 21 days. Kidney biopsies were processed to transmission electron microscopy (TEM) and ultrastructural pathology examinations. Exposure to ZnO NPs‐induced ultrastructural alterations in the proximal convoluted tubules (PCTs) and to lesser extent in the distal ones (DCTs), while the loops of Henle were almost not affected. The glomeruli demonstrated dilatation, partial mesangial cells loss, matrix ballooning, slits filtration widening, and basement membrane thickening. Moreover, PCT revealed cytoplasmic necrosis, vacuolation, erosion, and disorganisation of the apical microvilli together with mitochondrial swelling and cristae destruction. The nuclei of the renal cells exhibited nuclear deformity, heterochromatin accumulation, and apoptotic activities. The findings indicate that ZnO nanomaterial have the potential to affect the nephron ultrastructure suggesting alteration in the kidney functions. More work is needed for better understanding the toxicity and pathogenesis of ZnO oxide nanomaterial.