Dysfunction of mitochondria as aresult of a long-term influence of micro-dose of polycyclic aromatic hydrocarbons and nitrosamines on the organism
Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, street Kosygin, 4, Moscow, 119334 Russia
The consequences of long-term exposure to polycyclic aromatic hydrocarbons (PAHs) and nitrosamines (NA) on the body began to be studied in detail more than 100-150 years ago [Proctor R. N., 2004; Scanlan R. A., 2004]. The researchers' interest in these toxicants is associated with the high carcinogenic properties of PAHs and NAs. The bulk of PAHs in the environment is of anthropogenic origin. The main sources of PAHs are: household, industrial discharges, wash-outs, transport, accidents. The anthropogenic flux of PAHs, in particular benzo(a)pyrene (BP) is approximately 30 tons a year [Larin S. A. and co-authors, 2005]. Currently, the contamination by polycyclic aromatic hydrocarbons (PAHs) is global. Their presence is found in all elements of the natural environment (air, soil, water, biota) from the Arctic to Antarctica. Not less toxic nitrosamines (NAs). A large number of stands out with the exhaust gases and, finally, a huge number NAs are in the air smoke-filled rooms. Prolonged exposure to PAHs and even with tiny doses can lead to the development of a number of pathological conditions [Halliwell B. J, Gutterige M. C., 1985]. One of the most dangerous effects of prolonged exposure to these toxicants into the body is to reduce the reactivity of the immune system [N. Harper et al., 1996; Zhigacheva I. et al, 2002]. No less important indicator is the energy status, which determines the adaptive capabilities of the organism. No less important indicator is the energy status, which determines the adaptive capabilities of the organism. In this regard, our goal was to study the energy status of rats that have been long by exposure an artificial gas-air mixture containing the same amount of PAHs and HAs that is contained in the air of the industrial zone, near busy highways or in smoky rooms. The prolonged exposure on rats an artificial gas-air mixture containing microdoses of polycyclic aromatic hydrocarbons and nitrosamines resulted in a change in the energy of the mitochondria. The rates of oxidation of succinate decreased 1.5 times. At the same time, the efficiency of oxidative phosphorylation decreased by almost 2.5 times. In addition in the liver tissue, the EPR signal with g = 1.94,caused by iron-sulfur proteins of the mitochondrial membranes, was incident by 14%, which may indicate activation of apoptosis. Changes in the energy of liver mitochondria were comparable with changes in the activity of enzymes of the energy metabolism of peripheral blood lymphocytes: the activity of succinate dehydrogenase (SDG) and α-glycerophosphate dehydrogenase (HDG) in animals exposed to a gas-air mixture decreased by 1.5 and 2.0 times, respectively. It is suggested that changes in the energy of mitochondria may be due to activation of lipid peroxidation (LPO), the intensity of which increased 6.5-fold.