Abstract: This work was performed to explore the antihypoxia activity of yak blood oligopeptides and to elucidate the underlying mechanism. A total of 75 mice were randomly divided into hypoxia model, positive control (Rhodiola rosea L. roots) and high-, middle-, and low-dose yak blood oligopeptide groups. All mice were administered by gavage for 30 continuous days. At 60 min after the last administration, they were kept in airtight volumetric flasks until they stopped breathing and then myocardial and brain tissues were harvested immediately for the measurement of biochemical parameters. The results showed that yak blood oligopeptides had good antianoxic activity, and could protect brain and heart tissues of mice from atmospheric hypoxia. Compared with the model group, yak blood oligopeptides at high dose could significantly reduce malondialdehyde (MDA) content (P < 0.01), H2O2 level (P < 0.01) and lactate dehydrogenase (LDH) activity (P < 0.01) in brain and myocardial tissues of atmospheric anoxia mice, improve superoxide dismutase (SOD) activity (P < 0.01), glutathione peroxidase (GSH-Px) activity (P < 0.01 for myocardial tissue, P < 0.05 for brain tissue) and catalase activity (P < 0.01), and increase the content of adenosine 5’-triphosphate (P < 0.01). The above results showed that yak blood oligopeptides could alleviate oxidative stress injury caused by hypoxia in the body, and the mechanism may be related scavenging free radicals, inhibiting lipid peroxidation, and maintaining antioxidant enzyme activities and normal oxidative phosphorylation in mitochondria.

Key words: yak blood oligopeptide, antihypoxia activity, free radicals, lipid peroxidation, antioxidant enzyme