Effect of long-term inhalation exposure to cadmium oxide fumes on cardiac muscle ultrastructure in rats.

The ultrastructure of the cardiac muscle of rats exposed 5 h daily, 5 days a week to cadmium oxide (CdO) fumes at a concentration of 0.16 mg Cd/m3 for 3 and 6 months and at a concentration of 1 mg Cd/m3 for 3 and 4 months has been evaluated. The structure of muscle cells, arterioles and capillaries remained unchanged. There were distinct alterations of the intercalated disc structure dependent upon the level and time of exposure. The damage to intercalated discs varied from the enlargement of the fissure between membranes (within unspecialized segments) to disruption of the complex junctions.