Effects of Cd2+ and two cadmium organic complexes on isolated rat liver mitochondria

Effects of Cd2+ and two complexes of bivalent cadmium with 1,3-bis(4-chlorbenzylidenamino)-guanidine and anabasine on ion permeability of the inner membrane and respiration of isolated rat liver mitochondria were studied. Starting from 5 microM, Cd2+ decreased state 3 and DNP-stimulated respiration of mitochondria and increased their state 4 respiration. At 30 microM, Cd2+ decreased state 4 respiration. The complexes, particularly complex of Cd2+ with 1,3-bis(4-chlorbenzylidenamino)-guanidine, inhibited the mitochondrial respiration at lower concentration of Cd2+. Nonenergized mitochondria incubated in media containing 125 mM of NH4NO3 or KNO3 showed more pronounced swelling in experiments with 10 microM of the complexes than with Cd2+. The complexes produced swelling of the mitochondria energized by 5 mM of succinate and incubated in medium containing 25 mM K-acetate and 100 mM sucrose. Uptake of 137-Cs by succinate-energized mitochondria in the presence of 10(-8) M of valinomycin was substantially decreased in experiments with 10 microM of the complexes than with Cd2+. Ruthenium red (7.5 microM) prevented this effect with 10 microM of complex of Cd2+ with 1,3-bis(4-chlorbenzylidenamino)-guanidine and especially complex of Cd2+ with anabasine and Cd2+. These results indicate that the cadmium organic complexes affect respiration and perturb ion permeability significantly stronger than Cd2+.