Effects of Chronic Low-Dose Cadmium Exposure on Renal Morphology, Histology, and Trace Element Homeostasis, and...

Cadmium (Cd) is an environmental pollutant with a high affinity for the kidney, where it preferentially accumulates and may induce structural and biological alterations. This study aimed to evaluate the cumulative renal effects associated with low-dose Cd exposure, as well as the potential for recovery after cessation of exposure, either spontaneously or with zinc supplementation. Forty-two pubertal male Wistar rats were divided into seven groups: a control group; three groups exposed to Cd (10 μg/kg/day) for 1, 2, or 3 months; two groups exposed to Cd for 3 months followed by a 1-month recovery period, either without or with zinc supplementation (0.5 mg/kg/day); and a zinc-only group. Body and kidney weights, renal morphometry, intrarenal concentrations of Cd and essential trace elements, and renal histopathology were assessed. Low-dose Cd exposure was associated with a progressive decrease in body and kidney weights, a time-dependent accumulation of Cd in renal tissue, alterations in mineral content, and histopathological changes predominantly affecting the tubulo-interstitial compartment. Spontaneous recovery appeared partial, whereas zinc supplementation was associated with improvements in morphometric, biochemical, and histological parameters. These findings suggest that low-dose Cd exposure is associated with renal alterations and that zinc supplementation may contribute to partial recovery of these changes following exposure cessation.