Swimming Up-regulates PI3K-AKT Signaling Pathway And Improves Myocardial Insulin Resistance In Spontaneously Hypertensive Rats

Objective:Aerobic exercise can reduce cardiovascular disease risk factors,reduce the morbidity and mortality of cardiovascular disease.hypertensive as a kind of cardiovascular disease,its incidence is rising.Previous studies have found that zxf room exercise can significantly improve the spontaneously hypertensive rats myocardial insulin resistance,but the exact mechanism is unclear.based on the previous studies,this study further explore movement improve spontaneously hypertensive rats myocardial function and mechanism of insulin resistance,provide experimental basis and theoretical support for the movement control hypertensive.Methods:Based on the 4 weeks of male rats as the research object,a total of 25,divided into three groups:normal blood pressure control for 9(WKY),quiet spontaneously hypertensive group is 8(SHR),spontaneously hypertensive group of 8(SHR+E).use the swimming movement way,adaptive training a week later,the train six days a week,90 min training every day,for 8 weeks.After the completion of the movement,oral glucose tolerance test(OGTT)and insulin sensitivity experiment(IST),the changes of hemodynamic parameters detection of myocardial,HE dyeing observation the changes of myocardial morphology in spontaneously hypertensive rats,immunohisto chemistry and WesternBlot method to detect myocardial tissue PI3K and Akt,eNOS protein expression.Result:1.Oral glucose tolerance test(OGTT)show that:SHR compared with WKY group,glucose after lavage in 90 min and 120 min,blood sugar to keep at a high level(p<0.05),SHR+E compared with SHR group,glucose after lavage has obvious drop(p<0.01);IST,according to the results,after 30 min,60 min and 90 min,SHR group compared with WKY group,SHR group rats blood glucose by 9%,13%and 18%(p<0.01);Insulin after 30 min,60 min and 90 min,SHR+E group compared with SHR group,SHR+E group rats blood glucose is low 6%,7%and14%,(p<0.01).That show SHR rats have whole insulin resistance,after swimming training can effectively improve the insulin sensitivity.2.HE staining were observed found that:WKY group of myocardial cell morphology was normal,muscle wire density is big,SHR group,the myocardial cell morphology change,muscle silk dissolved,appear larger stripe gap between myocardial cells;After exercise intervention,SHR+E group,the myocardial cell conditions improved significantly,myocardial cell morphology has obviously improved,myocardial cell,That show SHR rats myocardial cell morphology of damaged phenomenon,after swimming exercise can effectively repair SHR myocardial morphology.3.Hemodynamics results show that:SHR compared with WKY group,heart rate(HR)decreased(p<0.01),mean arterial blood pressure(MABP)increased(p<0.001),Left ventricular systolic pressure(LVSP)increased(p<0.001);left ventricular end-diastolic pressure(LVEDP)increased(p<0.001);After 8 weeks swimming,SHR+E group compared with SHR heart rate(HR)decreased(p<0.01),mean arterial blood pressure(MABP)decreased(p<0.05),Left ventricular systolic pressure(LV SP)increased(p<0.001),left ventricular end-diastolic pressure(LVEDP)decreased(p<0.05),Left interior maximum rate of pressure rise(+dp/dt)increased(p<0.05),Left indoor pressure drop of the maximum rate(-dp/dt)increase(p<0.001,suggesting exercise intervention makes SHR rats ventricular function improved.4.Immunohistochemical results showed that:each group in the rat heart tissue PI3Kand Akt,eNOS to be expressed,SHR compared with WKY group,the average optical density value of PI3Kand Akt protein reduce(p<0.01),the expression of eNOS protein reduce(p<0.001);After swimming,SHR+E group compared with SHR group,the average optical density value of the PI3K protein increased(p<0.01),Akt,eNOS protein increased(p<0.001)5.Western Blot,SHR group compared with WKY group,PI3K and Akt protein expression reduced in myocardial(P<0.01),eNOS expression reduce,(P<0.001);After swimming,SHR+E group compared with SHR group,PI3K and Akt protein expression increased(P<0.01),eNOS protein expression increase(P<0.001),suggesting exercise intervention could effectively increase PI3K/Akt signaling pathway6.NO release results show that:SHR compared with WKY group,NO release reduce in the myocardial(p<0.05);After 8 weeks of swimming exercise intervention,SHR+E group compared with SHR group,NO release increase(p<0.05);Instructions after swimming exercise can increase the spontaneous hypertension of NO release,likely related to the movement raised eNOS protein expression.Conclusion:1.Swimming exercise can effectively repair the SHR rats myocardial morphology,improve heart function,reduce myocardial insulin resistance,increase myocardial insulin sensitivity,its mechanism may be related to sports increase PI3K,Akt,eNOS increases.likely relate to the PI3K/Akt signal pathway.