[Tricarboxylic acid cycle in energy metabolism and antioxidant cell defense in acute hypoxia].

The object of this study was to investigate the effects of exogenous succinate (SC) and alpha-ketoglutarate (KGL) on intensity of NO metabolism, lipid peroxidation and antioxidant enzymes activity in rat liver tissues under acute hypoxia (AH). Six groups of Wistar male rats participated in the study. Animals of Gr. I underwent i.p. saline injection, Gr. II--saline injection and AH (inhalation of 7% O2, 30 min). Gr. III and IY were examined after i.p. injection of SC (50 mg/kg) or KGL (200 mg/kg) and AH test; Gr. Y-after i.p. injection of SC with alpha- beta-adrenoblockers phentolamine and obzidane (2 mg each) and AH test, Gr. 6-after i.p. injection of KGL with M- and N-cholinoreceptor blockers athropine (5 mg) and benzohexonium (10 mg) and AH test. It was shown that AH provoked the decrease of NO production by 34%, the addition of SC augmented twice the nitrite anion content, the addition of KGL--in three times. KGL decreased malon dialdehyde content under AH by 32% and SC- by 25%. The least level of lipid peroxidation was registered in Gr. YI. Adrenoblockers did not influence on antioxidant enzymes activity under AH, but cholinoblockers completely eliminated the increase of SOD, catalase, glutathione peroxidase and glutathione reductase activities under KGL treatment. We conclude that nitric oxide production under alpha-ketoglutarate influence is mediated by cholinoreceptors.