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In 1972 Allen Ct al. have reported light emission generation, called chemiluminescence (CL), in leukocytes after phagocytic stimulation with bacteria. Since that time CL has been shown in numerous publications as a method for studying the phagocyte deoxygenating activity (RC.Allen, 1976;1981;1986; P. FaIk, 1985; J. Lindena et al., 1987, M. Ristola and H. Rero, 1989, N. Fionenko and N. Sa1aDS1Cy, 1991, 1992, etc.). Resting neutrophils consume little amount of oxygen since they rely mainly on glycolysis for AlP production. As a part ofthe immune system, phagocytes react to almost all alterations in the host organism. Neutrophils are among the first cells which react to infection and tissue injuiy. Being activated these cells increase the 02 consumption up to twenty times (this is less marked in macrophages). This process is known as the oxidative burst (OB). The net effect ofthis oxidizing activity is a large production offree radicals-reactive oxygen species (ROS), which have high damage potential. ROS hyperproduction (due to some dysfunctions) leads to tissue destruction while lack of these cytotoxic agents may cause increased susceptibility to infection. As demonstrated in chronic granulomatous disease, a condition in which the patient's PMNL (polymorphonuclear neutrophils) and monocytes can phagocytose microbes but are unable to activate redox metabolism, oxygenation activity is necessaiy for effective microbicidal action. Radicals react with nonradicals in several ways. The main feature of this process is that it develops as a chain reaction, where one radical begets another one from a nonradical (B. Halliwell, 1991). Free radical release in both neutrophils and macrophages is due to the activation of an enzyme complex associated with the plasma membrane. The plasma membrane cells, as it was first shown ( B.M. Babior et al. 1978) ,possess a special enzyme nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase. The activation of this enzyme could be via cycloxigenase and lipoxigenase pathway ; upon activation it yields superoxide anion by a one-electron reduction of dioxigen. NADPH-oxidase is a membrane bounded enzyme complex, which consists at least from three components: cytochrome b (with low potential), cytochrome 1,245 and a 44-45 KDA flavoprotein (Cross A.R., 1986). On activation of the enzyme, electrons are transferred from NADPH via the flavoprotein to the cytochrome b, which then serves as a terminal electron donor to dioxigen.
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