[Complexes of nitric oxide with hemoglobin and paramagnetic metalloenzymes in the brain and blood of mammals after intermittent hypoxia].

Aim: To investigate an effect of hypoxia on the formation of nitric oxide (NO) in the brain and blood of rats and an influence of L-NNA, the NO-synthase inhibitor, and sodium nitrite on NO generation in separate and simultaneous introduction of these compounds in the animal body.

Material And Methods: Experiments were conducted on 42 rats of Krushinsky-Molodkina (K-M) line without adaptation to hypoxia and short-term adaptation to hypobaric hypoxia. Animals were intraperitoneally injected with sodium nitrite (0.

Relation of biological activity of mutant forms of recombinant human tumor necrosis factor alpha and accumulation of sphingosine in murine liver.

TNF-alpha induced sphingomyelin hydrolysis by sphingomyelinase and both sphingosine and ceramide generation have been reported to be implicated in a number of TNF-alpha responses, including cytotoxicity and apoptosis. We found that sphingosine, a highly cytotoxic product of enzymatic degradation of sphingomyelin, is accumulated in liver of mice treated with TNF-alpha. To determine the role of sphingosine in TNF-alpha toxicity, TNF-alpha mutants differing in their cytotoxicity to L929 cells as well as haemorrhagic tumor necrosis, tumor regression and lethal toxicity in mice were used in our experiments.