Cadmium induces ultrastructural changes in the hepatopancreas of the freshwater crab Sinopotamon henanense

Cadmium (Cd) is one of the most common pollutants in the environment and induces a range of tissue changes or damages and organ dysfunction. To explore the morphological changes in the hepatopancreas, freshwater crabs Sinopotamon henanense were exposed to water-borne Cd for 72 h. Histologically, cellular swelling and apoptosis were observed, and to a lesser degree, necrosis. Ultrastructurally, there were changes in the nucleus and mitochondria with swelling, membrane disruption, cristae shorten or disappearance and mitochondria rupture. Numerous autolysomes occurred and may contribute to the damages to the crab treated with high Cd concentrations. The cell coat and P/Ca granules were gradually reduced when the Cd concentration increased. The RER displayed twisting, expansion with ribososomes detachment and crack in crabs treated with high Cd concentration. Saccules, vacuoles and vesicles of the Golgi complex may disaggregate expressly in the highest Cd group. Microvilli were not the first affected target. Thus, different organelles and cellular structures of freshwater crab were damaged at different stages of the Cd-induced injury. Apoptosis was the notable cell damage induced by Cd and presumed to be ascribed to various organelle injuries. Mitochondria are probably the primary and the critical target of Cd intoxication.

► Cellular swelling, apoptosis and necrosis were induced by Cd in the hepaopancreas in vivo.
► Various kinds of organelles were damaged.
► The damages of different organelles were addition or synergism and endangered the crabs.
► Mitochondria were the key target damaged by Cd.