[Effect of hypoxic hypoxia on development of atherosclerosis in rabbits]

The study was aim a evaluating effects of intermittent hypoxic training on experimental atherosclerosis. In a three-month experiment rabbits (n = 12) were fed with cholesterol (200 mg/kg of the body mass) and "ascended" to the altitude of 6000 m for 6 hrs per a day. The controls (n = 10) were fed with cholesterol only. Investigated was the dynamics of a spectrum of plasmatic lipoproteids, lipid peroxidation, morphologic alterations in the aorta and mononuclear phagocytes. Intermittent hypoxia caused less evident than in the control increases in total cholesterol (20.6 +/- 2.3 vs. 33.1 +/- 1.9 mmol/l, p < 0.05) and LDL cholesterol (19.4 +/- 2.2 vs. 32.3 +/- 2.3 mmol/l, p < 0.05). Unlike the controls, there were no atherosclerotic plaques in the aorta of the experimental rabbits. Atherosclerosis was diagnosed just by tiny dot- and strip-like lipid patches smaller in size when compared with the control group in which massive diffuse lipid deposits were found. The affected aortic areas made up 13.5% in the experimental group and 65% in the control. Hypoxic training brought about activation of the antioxidant system and was propitious for functional activity and oxygen-dependent and -independent metabolism of phagocytes. Exposure to hypoxia reduced the number of lipid inclusions in monocytes (303.0 +/- 12.5% vs. 370.0 +/- 4.5% in the control, p < 0.05), prevented the dramatic inhibition of the cells observed in the animals fed with cholesterol and, eventually, blocked up formation of spumescent cells. These data infer that intermittent chamber hypoxia exerts the antiatherogenic effect on experimental atherosclerosis.