[Effects of melatonin on oxygen-dependent processes].

Original and literature data on melatonin effects on various oxygen-dependent processes, in particular, blood oxygen transport and the free-radical reactions, are analyzed. Melatonin influences the oxygen binding properties of hemoglobin by changing hemoglobin oxygen affinity and optimizes the process of tissue oxygenation and prooxidant--antioxidant balance by reducing oxygen participation in free-radical processes.

[Erythropoietin and blood oxygen transport: new sides of well-known problem].

Original results and literature data on the erythropoietin effects and mechanisms of action are analyzed. The action of this substance on blood oxygen transport is not only manifested by direct change in hemoglobin concentration and, correspondingly, by increased oxygen capacity, but is also mediated by modulators of hemoglobinaffinity to oxygen, in particular, via nitric oxide effect on hemoglobin.

[Effect of melatonin on the blood oxygen-carrying function and prooxidant-antioxidant balance after lipopolysaccharide injection].

Effects of melatonin on the blood oxygen-carrying function and prooxidant - antioxidant balance in the organism were studied 12 h after lipopolysaccharide injection in rabbits. The treatment with melatonin (intraperitoneally in a dose of 4 mg/kg) before endotoxic lipopolysaccharide injection (intravenously 500 microg/kg) improved oxygen transport function of the blood, increased the hemoglobin-oxygen affinity, decreased nitrates/nitrites level, reduced the gain of free-radical processes, and increased the level of antioxidant protection factors in test animals. It is concluded that melatonin modulates the blood oxygen-carrying function and prooxidant - antioxidant balance through NO-dependent mechanisms, thus reducing the negative action of endotoxin on the organism.

[Erythropoietin influence on oxygen transport function of blood and prooxidant/antioxidant balance in rabbits under lipopolysaccharide injection].

We aimed to study the erythropoietin influence on oxygen transport function of blood and prooxidant/antioxidant balance in rabbits under lipopolysaccharide injection. Recombinant human erythropoietin-alpha was administered intraperitoneally in the dose 1000 U/kg 30 minutes before intravenous injection of 500 mkg/kg lipopolysaccharide from E. coli.