Impact Of Intermittent Hypoxia Training On Tyrosine Phosphorylation Level Of Myocardial Peptides In Obesity Mice

Background: Obesity that is often caused by high fat diet has induced many cardiac hazards in worldwide. The cardiac structure in obesity people transformed greatly when compares to ordinary people. What is more, cardiac structure turned into necrosis, apoptosis, mitochondria multiplication and arrangement disorder, cardiac hypertrophy and arrangement disorder which lead to cardiac function decompensation in different degree. There are evidences on intermittent hypoxia training, which can help to enhance systolic capacity, hypoxia tolerance and maintain balance between antioxidation and compensatory ability. Anyhow, obesity and intermittent hypoxia training both impact on cardiac structure and function by suppressing or activating on signal pathway in cardiac cells. Tyrosine signal pathway is a major pathway on cellular growth differentiation. The substrate phosphorylation level of tyrosine reflects relating signal pathway activation, transmission and show cellular growth differentiation indirectly. By testing the substrate phosphorylation level of tyrosine, we can compare impact of different methods on this pathway.Methods: we made models by high fat diet and intermittent hypoxia training on KM female mice. Healthy female KM mice were divided into 4 groups randomly (6 mouse in each group): Control mice were fed by basic diet; High fat diet mice were fed by high fat, high calorie, high glucose diet; Intermittent hypoxia training mice were fed by basic diet and accepted intermittent hypoxia training in hypoxia cabinet every day; High fat diet+ Intermittent hypoxia training mice were fed by high fat diet as high fat diet group and accepted intermittent hypoxia training group as intermittent hypoxia training as described before. We monitored mice weight change during experiment procedure every week. All mice were sacrificed after 40 days and hearts were taken frozen in ultra low temperature -70℃. Cardiac peptides were separately extracted for MS examination to determine tyrosine phosphorylation. Mice's bloods were preserved to test serum leptin concentration. Parts of mice's left ventricular samples were stained by HE and did microscopic observation. Intermittent hypoxia training can enhance serum leptin level while high fat diet cannot make it.Results: High fat diet has obviously impacts on phosphorylation level of tyrosine which focus in necrosis, mobilization, Ca²⁺ overloading and phagocytosis. On the opposite, intermittent hypoxia training has obviously impacts on phosphorylation level of tyrosine which focus in cell movement regulation, glucose utilization. Both high fat diet and intermittent hypoxia training have impact on phosphorylation levels of tyrosine which modify cardiac cells and extracellular matrix adhesion; they also activated ERK1/2, PI3K which are important intracellular signal transmission kinase. Conclusion: High fat diet and intermittent hypoxia training both have impact on phosphorylation level of tyrosine in process of cardiac reconstruction. Leptin may play as extracellular signal during process of intermittent hypoxia training. Intermittent hypoxia training can partly suppress necrosis, apoptosis and cardiac function decrease that caused by high fat diet.