Influence of montmorillonite on cadmium accumulation in carp, Carassius auratus

The present study was designed to test the influence of montmorillonite (MMT) on cadmium accumulation in different tissues of Carassius auratus. 180 normal healthy C. auratus were randomly divided into four groups. They were fed with normal diet, normal diet supplemented with MMT (0.5%), high-cadmium (cadmium chloride, 120 mg/kg) diet and high-cadmium diet supplemented with MMT (0.5%). After 60 days, cadmium concentration in several tissues were measured by eletrothermic atomic absorption spectrophotometry, metallothionein contents were determined using the Cd-chelex assay and histopathological alterations of kidney were observed. MMT inhibited cadmium accumulation in kidney, intestine, liver, spleen, blood, gills, spermary, ovary, brain, bone and muscles of C. auratus. Metallothionein levels in liver, intestine and muscle decreased and pathological changes of kidney were reduced by MMT addition. Thus, MMT protected tissues of C. auratus from cadmium accumulation and damage.