Cytotoxicity of Nitric Oxide and Hydrogen Peroxide

摘要: Nitric oxide (·NO) is well defined as an important effector molecule in biological systems. Secreted from various cell types, ·NO contributes to a variety of physiological and pathophysiological processes [22]. Despite its function the control blood pressure, platelet aggregation neurotransmission, which are mediated via activation soluble guanylate cyclase, has been shown be potent modulator cytotoxic activity macrophages [12; 21]. The mechanisms by bactericidal tumoricidal potential still poorly understood. Diverse molecular targets have postulated exist for attack on surface inside cells such thiol groups proteins yielding S-nitrosothiols [14]. In addition membrane-linked targets, suggested inhibit mitochondrial respiratory chain, DNA protein synthesis iron metabolism [11]. Besides these effects, could direct effects ·NO, increasing number studies postulates that cytotoxicity enhanced chemical interactions with oxygen reactive species form other potentially toxic radicals. For example, reacts superoxide anion (O2 −) forming peroxynitrite (ONOO−) decays, once protonated, very hydroxyl radical (·OH) nitrogen dioxide (·NO2) [1]. Increased reactivity due interplay O2 − ONOO− pathway supported systems [28; 25; 4; 5].