| Objective:Hypertension is a common chronic cardiovascular disease, which has a serious impact on human health. Long term continuous high blood pressure may decrease the function of the heart and the structure of the heart, so it is very significant to study the early symptoms of hypertension and the prevention of the occurrence of complications. Studies have found SHR rats myocardial mitochondrial function barrier, show the SHR rats myocardial mitochondrial respiratory lining the decrease of ATP synthase. Load intensity exercise may increase aging rats of respiratory chain enzymes activity and strengthen the function of mitochondria, but whether exercise can increase SHR rats myocardial mitochondria of compound enzyme activity, improve mitochondrial function, and improve heart function and reduce the myocardial injury research has not reported. Therefore, this experiment by building long-term aerobic exercise SHR rats models, observed aerobic exercise on SHR rats myocardial mitochondrial respiratory chain enzymes Ⅱ～Ⅳ activity and the influence of myocardial mitochondrial oxygen free radical metabolism index, preliminary discussion of aerobic exercise on SHR rats the protective effect and mechanism of myocardial mitochondria, for aerobic exercise provide certain theoretical basis for the prevention and treatment of high blood pressure.Methods:Four week old SHR rats were randomly divided into 9 rats in SHR quiet group,11 rats in SE group. Four weeks old WKY rats were randomly divided into 7 rats in WE group and 9 rats in WKY group. Cage feeding, each cage 4-5 only, room temperature 20 degrees -22 degrees, relative humidity 40%-55%, light time lOh/d, and free drinking food. Before training for a week of adaptive training, training methods of swimming, the first day of 10 minutes, second days and 20 minutes, has been to sixth days and 60 minutes. Long term aerobic exercise SHR model was constructed using nine weeks of swimming, starting at 7 points per night. First,2 weeks of training 60min, third,4,5,6 weeks 90min, seventh,8,9 weeks 120min. After nine weeks of swimming exercise,12h was determined by the method of glucose tolerance and insulin sensitivity.24h hemodynamic analysis of the left ventricular systolic pressure, diastolic blood pressure and heart rate and other indicators of cardiac function, using transmission electron microscope observation of myocardial mitochondria and myocardial ultrastructure in rats. By the late spectrophotometric method for the determination of enzyme to rat myocardial mitochondrial respiratory chain activity and oxygen free radical index IV.Results:1 After nine weeks of aerobic exercise, the body weight of rats increased in different levels. (251.31 from 111.85 257.59 136.62 rats (to 282.87 133.43 WKY rats weight from 2.93+(g) growth+20.50 (g),112 percent increase in SHR rats weight from 112.08+3.64 (g) growth to 271.79+756 (g), an increase of 142% and WKY rats compared to the growth rate significantly increased); we weight from+4.40 (g) growth to+10.50 (g), the growth of 89%, and WKY rats compared to the growth rate significantly reduce); se rats weight+6.35 (g) growth to+16.20 (g), the increase of 124% and SHR rats compared to the weight growth rate decreased significantly. It shows that aerobic exercise can obviously inhibit the growth rate of the weight of rats. Age differences exist in the body weight of rats in each group, compared with WKY rats, the body weight of SHR was significantly lower than that of the WKY rats body weight (P<0.01); compared with SHR rats, body weight of rats fed with Se was significantly lower than that of the body weight of SHR and from week 6 began to appear significant difference (P<0.01). Obviously, this experiment data show that aerobic exercise can significantly reduce the body weight of SHR rats increased.2 OGTT test found that, compared with WKY rats, SHR rat’s blood glucose in 60min,90min and 120min recovery rate significantly reduced. The recovery rate of 60min,90min and 120min in WE group was increased, but no significant difference. Compared with SHR rats, the recovery rate of blood glucose in 60min,90min and 120min was significantly increased in SE rats, and there was significant difference between 120min and. The experiment data showed that SHR rats decreased glucose tolerance, while aerobic exercise can improve the glucose tolerance level of SHR rats.3IST test showed that the blood glucose level of SHR rats decreased significantly after insulin injection, respectively, in 30min (P<0.01) and 60min (P<0.05) (WKY). Compared with SHR rats, the blood glucose level of SE rats decreased significantly after insulin injection, respectively, in 30min (P<0.01) and 60 min (P<0.05). The experiment data show that aerobic exercise can improve insulin sensitivity of SHR rats.4. Myocardial ultrastructural observation showed, compared with WKY rats, SHR rats myocardial disorder of myofibrils, morphologically abnormal sarcomere structure, nuclear structure part missing, incomplete, mitochondria arranged irregularly and decreased in number. Compared with SHR rats, Se rats left ventricular myocyte myofibril arranged was neat, sarcomere structure integrity, nuclear structure significantly changed for the better, increase in the number of mitochondria, arranged in an orderly manner. It showed that the left ventricular myocardium of SHR rats was damaged, the mitochondrial structure was abnormal, and the aerobic exercise could reduce the degree of myocardial injury, and improve the structure of mitochondria.5. Hemodynamic indexes analysis, compared with WKY rats, SHR rats left ventricular systolic blood pressure, diastolic blood pressure and heart rate were significantly increased (P< 0.01); compared with SHR rats, Se rats left ventricular systolic blood pressure, diastolic blood pressure and heart rate were significantly reduced, showed that aerobic exercise can improve heart function of spontaneous hypertension rats (SHR).6. Myocardial mitochondrial respiratory chain enzyme activity detection found that compared with WKY rats, SHR rats myocardial mitochondrial enzyme complex and the compound enzyme IV activity decreased significantly (P< 0.01), and that of myocardial mitochondrial complex II activity and enzyme complex III activity decreased slightly, but no significant difference. Compared with SHR rats, se of mitochondria in rats with compound enzyme and the compound enzyme IV activity increased significantly (P< 0.01), and myocardial mitochondrial complex II activity and enzyme complex III activity increased slightly, but no significant difference (P> 0.05). Showed that aerobic exercise may improve the myocardial mitochondrial enzyme complex and enzyme complex IV activity and improve mitochondrial function. 7 Myocardial mitochondrial free radical metabolic index analysis, compared with WKY rats, SHR rat myocardial mitochondrial SOD significantly decreased (P<0.01). After aerobic exercise, the SOD activity of myocardial mitochondria in SE rats was significantly increased (p<0.01). Compared with WKY rats, the myocardial mitochondrial MDA was significantly increased in SHR rats (P<0.01), and MDA was significantly decreased in group SE compared with group SHR rats (P<0.01). It showed that aerobic exercise can significantly improve the level of myocardial mitochondrial free radicals in SHR rats.Conclusion:1 In myocardium of SHR cells myofibrillar disarray, deletion constructs, decline in cardiac function, myocardial damage, structural abnormalities of myocardial mitochondria, mitochondrial enzyme activity decreased myocardial mitochondrial oxygen radical dynamic disorder.2 Aerobic exercises may improve the ultrastructure of left ventricular myocardial cells in SHR rats, improve left ventricular function and decrease heart rate. At the same time, by increasing the activity of SHR rats myocardial mitochondrial enzyme IV, improve the function of respiratory chain, improve myocardial mitochondrial dysfunction in SHR rats and restore the dynamic balance of oxygen free radicals in the body, and then up to the protective effect on myocardial. |
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