Ultrastructural changes in rat alveolar macrophages exposed to oxides of copper and cadmium

The morphological effects of single intratracheal injections of copper oxide (CuO) and cadmium oxide (CdO) (5 mg) on rat alveolar macrophages were studied. Rats sacrificed after a one week recovery period showed distinct morphological changes induced by CuO and CdO. Copper oxide induced hypertrophy of both the alveolar macrophages as well as the epithelial lining. The macrophages contained polymorphic nuclei with margination of the chromatin, crystalloid-like inclusions, concentric and parallel lamellar structures, lattice formationa and degenerative membranous structures. After CdO treatment, a slight increase in the number of alveolar macrophages and an attenuated thickening of the epithelial wall were noted. Two types of macrophages were identified: one type was large in size, with numerous vacuoles, electron dense aggregations, phagocytized mitochondria and fragmented chromatin. The other type was smaller in size, with fewer vacuoles, a distinct rough endoplasmic reticulum, mitochondria, and a highly convoluted plasma membrane. The results were suggestive of degenerative morphological alterations due to CuO and CdO treatments which were incompatible with normal macrophage function.