THE INTRACELLULAR-DISTRIBUTION OF COBALT IN EXPOSED AND UNEXPOSED RAT MYOCARDIUM

The intracellular distribution of cobalt was analysed in the myocardium of exposed and unexposed rats. The exposed rats were given a dietary cobalt supplementation of 40 mg CoS04-7 H20/kg body weight for 8 weeks. The mitochondrial fraction showed the greatest relative increase in cobalt: 0.09 ng/mg protein in the unexposed rats to 8.43 ng/mg protein in the exposed rats. In the exposed rats the submitochondrial particles had the highest levels of cobalt: 19.43 ng/mg protein, followed by the sarcoplasmatic reticulum: 12.3 ng/mg protein. The microsomal 44 000g supernatant also showed an increase, although the levels remained low (0.51 ng/mg protein in the exposed animals). Apparently the calcium-storing organelles had the highest levels of cobalt. This could affect calcium flux in myocardial cells and, secondarily, tension development in cardiac muscle. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.