Ikkert O. The influence of L-arginine and Nw-nitro-L-arginine on mitochondrial energy support of rats with different resistance to hypoxia

Ikkert O.V. The influence of L-arginine and Nw-nitro-L-arginine on mitochondrial energy support of rats with different resistance to hypoxia.- Manuscript. The Doctoral Dissertation on biological science on speciality 03.00.13 - physiology of humans and animals. Ivan Franko Lviv National University, Lviv, 2003. The dissertation is devoted to investigation of the influence of L-arginine (nitric oxide precursor) and NO-synthase blocator Nw-nitro-L-arginine (L-NNA) on processes of ADP-stimulated respiration, lipid peroxidation and antioxidant system activities with different resistance to hypoxia. Present study demonstrated that intraperitoneal injection of L-arginine (600 mg/kg) and L-NNA (35 mg/kg) can modulate mitochondrial energy support processes by changes of substrate oxidation ways, transaminases and succinatdehydrogenase (SDG) activity. Because L-arginine treated animals with high and low resistance to hypoxia were characterized decreasing of SDG activity and processes of oxidative phosphorilationunder succinate acid oxidation. L-NNA leveled this effects. L-arginine injection caused increasing of aminotransferases activity in low resistance animals under glutamate and malate and glutamate and pyruvate oxidation. It was shown that L-arginine stimulated calcium capasity of low resistance animals under succinate, ?-ketoglutarate, glutamate and pyruvate oxidation. On the contrary, decreasing of high resistance animals calcium capacity was conditioned by L-NNA under succinate, ?-ketoglutarate, glutamate and pyruvate and glutamate and malate oxidation. We have investigated the influence of intraperitoneal injection of L-arginine and L-NNA on antioxidant systems (the activity of superoxiddismutase (SOD), catalase (KAT), glutathione reductase (GR), glutathione peroxidase (GP) and ceruloplasmine) and processes of lipid peroxidation (the concentration of diens conjunctions and malonic dialdehyde) in rats with different resistance to hypoxia. Our results suggested that AOZ system activity depend on NO-ergic linkof regulation: L-arginine caused decreasing of lipid peroxidation processes in low resistance animals, but in high resistance animals this effect was obtained by L-NNA treatment. Stimulation of NO-synthase activity made for SOD and KAT inhibition and activation of glutatione link of AOZ system in high resistance animals. Low resistance animals had glutatione link of AOZ system activation under L-NNA treatment. A suggestion was made that mitochondrial processes in animals organisms with different resistance to hypoxia can be corrected by functional changes of NO-ergic link of regulation activity.