INTERACTION BETWEEN CADMIUM AND COPPER ON OSSIFICATION OF EMBRYONIC CHICK BONE IN TISSUE-CULTURE

To investigate the interaction between cadmium and copper in ossification, femurs from 9-day-old chick embryos were cultured for 6 days in the presence of 2-mu-M cadmium and/or 1-mu-M copper. It was found that cadmium + copper treatment caused interactively severe damage to osteogenic mesenchymal cells in the periosteum and a severe degenerative change in osteoblasts around the trabecula, resulting in severe impairment of ossification in the diaphysis. Cadmium content was increased by copper; however, copper content was unaffected by cadmium in the diaphysis. It was therefore considered that the copper-induced increase in cadmium content was a primary factor in the interactive toxic effect of the cadmium + copper treatment in ossification.