Disturbance of the functionality in immunocompetent organs of chickens due to accumulation of cadmium

The high toxicity, bioaccumulative and increased distribution of cadmium (Cd) in the environment, makes it the most dangerous to any biological system, including immune system in human and animals. The effect of dietary intake of Cd (8.25 mg per kg) on accumulation and distribution of this heavy metal in various tissues, and functional changes in organs of immunity (thymus, bursa of Fabricius, spleen) in 35-day-old broiler cockerels were investigated, using biochemical and immunological methods. Significant increases in the Cd concentration both in central immunocompetent organs (thymus, bursa of Fabricius) and peripheral (spleen) were established. Excessive tissue level of Cd induced the prooxidative effect of this heavy metal in the organs. It was manifested in an increase of cell membrane lipid peroxidation (the enhanced malondialdehyde (MDA) concentration) in immune system organs. The oxidative stress resulted in immunocompetent cell damage. The fall of vital dye absorptive ability of immunocyte indicated the increase in the injured cell number. This harmful effect is in accordance with T- and B (C3) - population prominent depletion, organ relative mass reduction, and growth retardation in chicks, and was established as a result of dietary Cd loading for 5 weeks of the experiment.