Aerobic Exercise To Improve Spontaneously Hypertensive Rats Myocardial Function And Mechanism Of Insulin Resistance

Objective:Insulin resistance can lead to the start and development of big diseases, such as Ⅱ type diabetes, coronary heart disease and high blood pressure etc. Insulin resistance, a kind of pathological condition, can be caused after cells’ insulin receptor or when signaling transduction is disturbed after the receptor. High blood pressure is one of high incidence of diseases. So previously, researches mainly focus on studying high pressure and blood vessel insulin, while only a few researches focus on studying myocardium insulin resistance. Recent researches show that there exists insulin resistance in rats with high blood pressure. A large amount of clinical examinations and experiments prove that doing exercises is the most economical, effective and secure way in improving insulin susceptibility. But there is only a small amount of researches on studying how much benefits the exercises will do to myocardium insulin of rats with high blood pressure. Besides, its mechanism is not clear. So this experiment pays much attention to what impacts exercises will make on myocardium insulin susceptibility of rats with high blood pressure and also explores the first-step discussion on its mechanism. Especially, the effects of the pI3K-Akt signaling pathway, the downstream of PPARy, will be discussed.Methods:Build a long-terme on myocardium Hemodynamic of rats with high blood pressure and what the effects of myocardium insulin susceptibility are. And test myocardium PPARy and Akt protein expressio aerobics model for rats with high blood pressure. Observe what impacts exercises will makn by using Western blot.Results:(1) Compared with rats in WKY group, the weights of rats in SHR group decrease greatly. But heart weights of rats in these two groups are almost the same. The ratio between heart weight and weight of rats in SHR group increases distinctly, which proves that rats with high blood pressure have myocardium hypertrophy. Exercises can decrease the weight, increase heart weight and increase heart coefficient of rats with high blood pressure. It may be concerned with adaptive myocardium hypertrophy caused by exercises, which is a kind of benign adaptation of heart (P<0.01,n=10)(2) Compared with rats in WKY group, the systolic blood pressure and diastolic blood pressure of rats at the same age in SHR group increase greatly. Compared with rats in SHR group, the systolic blood pressure and diastolic blood pressure of rats in exercises group decrease greatly (P<0.05, n=10). The above information proves that exercises can prevent high blood pressure.(3) Compared with rats in WKY group, blood sugar levels of SHR rats on empty stomach increase greatly (P<0.01,n=10). Compared with rats in SHR group, blood sugar levels of rats in exercises group decrease greatly (P<0.01,n=10). The above information proves that exercises can reduce blood sugar level on empty stomach of rats with high blood pressure.(4) The heart±LV dP/dtmax of rats in WKY group and in SHR exercises group beats quickly after injecting insulin (compared with SHR group after injecting insulin (compared with SHR group, P<0.05, n=8). The heart±LV dP/dtmax of rats in SHR group beats almost normally (P<0.05, n=8). Exercises can increase heart±LV dP/dtmax of rats in SHR group by insulin induction (P<0.05,n=10). The above information proves that exercises can increase myocardium and reduce myocardium insulin resistance.(5) Compared with rats in WKY group, Akt and PPARy protein expression of rats in SHR group decreases greatly (P<0.01,n=10). Compared with rats in SHR group, Akt and PPARy protein expression of rats in SHR exercises group increases greatly (P<0.01,n=10)Conclusions:We can come to the conclusions as follows:(1) Aerobics can reduce the systolic blood pressure and diastolic blood pressure of rats with high blood pressure, which can prevent high blood pressure in some degree..(2) There exists obvious myocardium insulin resistance in rats with high blood pressure, and myocardium insulin resistance is concerned with the decrease of myocardium Akt and PPARy protein expression.(3) Aerobics can improve myocardium insulin resistance significantly and increase myocardium insulin susceptibility, which may be concerned with the increase of myocardium Akt and PPARy protein expression after exercises.