| Objective:This report is to explore aerobic exercise improve MI rats cardiac CHAT/VACHT, M3R characterization and cardiac function and its possible mechanism.Methods:4 weeks experiment:SD male rats,3 months old,were randomly divided into control group (S),myocardial infarction group (MI),control+exercise group (SE), myocardial infarction+exercise group(ME),each 12.By increasing continuous treadmill exercise:start 10 min/day,at the rate of 10 m/min,slope of 0 °,ran a slope and speed gradually increased to 5-10% and 20,25 m/min, exercise duration from 10 to 20 min/day to 60 min/day,5 d/wkx 4 wk.Eight weeks experimentrats were randomly divided into control group(C)and myocardial infarction(MI), myocardial infarction+moderate intensity exercise group (ME1)and myocardial infarction+high intensity intermittent movement group(ME2). each 12.ME1 group after 1 wk to a treadmill exercise.1 wk for a fitness training(10 m/min,10 min x 5 d/d).Formal training, the initial speed for 10 m/min x 5 min.After 3 m/min increases gradually to 16 m/min,60 min/d(60-70%VO2max),5d/wk x 8awk. ME2 group after 1 wk to a treadmill exercise.1 wk for a fitness training(15m/min,30 min/d x5d).Formal training, starting speed 10 m/min x 10 min.With 25 m/min after x 7 min (85%-85%V02max);At 15m/min x 3min(50%-50% VO2max), ordinal alternates,60 min/d, 5d/wk x 8awk.After day, after the training record electrocardiogram and hemodynamic indexes, such as, the change of the reaction of rat cardiac function; Immediately after thoracotomy with heart, histologic production line, Masson staining, the microscopic observation heart tissue morphological changes such as the structure; Using Western Blot method to detect the heart parasympathetic nerve specific protein CHAT, VACHT, M3R,MEK1/2-ERK1/2,the Bcl-2/Bax expression, immunofluorescence technique to detect the heart M3R expression.Result:1. MI in rat myocardial CHAT and VCHAT expression significantly reduced,seriously damaged cardiac parasympathetic nerve,4 weeks aerobic exercise can significantly improve the CHAT and VACHT expression,improving the damaged cardiac parasympathetic nerve.2. The rat myocardial tissue structure MI lead to damage to the alternative fibrosis,a significant reduction in the cardiac function,4 weeks aerobic exercise significantly improving the structure of the damaged heart muscle tissue of rats,reduce the degree of myocardial fibrosis,reduce myocardial infarction size, effectively improve cardiac function.3. Immunofluorescence,according to the results of normal rat myocardial M3R few positive expression,main expression in myocardial cell membrane.Myocardial ischemia can lead to myocardial M3R expression increased significantly,4 weeks aerobic exercise can effectively stimulate the expression of myocardial M3R.4. Western Blot results showed that myocardial ischemia can lead to myocardial M3R expression increased significantly, by MEK1/2 channel;4 weeks aerobic exercise can effectively stimulate the expression of myocardial M3R,effective activation of MEK1/2,special effect on ischemic heart even more significant.5. Western Blot results showed that myocardial ischemia can lead to myocardial cell apoptosis,4 weeks aerobic exercise can effectively reduce the myocardial cell apoptosis,especially in pathological heart more prominent.6. Aerobic exercise can inhibit apoptosis of ischemic heart may be by raising M3R, activation of MEK1/2.7. Immunofluorescence show, immunohistochemical observation and Western Blot results and analysis show that myocardial M3R positive particles are mainly distributed on the myocardial cell membrane.Eight weeks of continuous and intermittent movement can effectively promote the expression of myocardial M3R, effect of two groups had no significant difference.8. MI can stimulate myocardial MEK1/2, p-ERK1/2 and ERK1/2 protein expression significantly low; Eight weeks of continuous and intermittent movement can further improve myocardial MEK1/2, p-ERK1/2 and ERK1/2 protein expression and effect of the two groups had no significant difference.9. MI can stimulate a significant rise in myocardial Bax protein expression,eight weeks of continuous and intermittent motion can significantly reduce its expression; MI can stimulate myocardial Bcl-2 expression and the Bcl-2/Bax ratio decreased significantly,eight weeks of continuous and intermittent movement significantly improve its expression. Shows that the continuous and intermittent movement can inhibit MI rat myocardial cell apoptosis, effect of two groups no significant difference10.MI heart the myocardial cell necrosis, and alternative fibrosis,eight weeks of continuous and intermittent motion can significantly reduce the collagen volume percentage (CVF),inhibit excessive proliferation of collagen,the effect of the two groups had no significant difference.11. MI heart LVSP and +dp/dtmax significantly reduced, a significant rise in LVEDP, seriously damaged heart function;Eight weeks of continuous and intermittent motion can significantly increase LVSP and +dp/dtmax,significantly improves cardiac function in rats,and the continuous movement of intermittent movement effect is more significant.Conclusion:4 weeks aerobic exercise can significantly increase the expression of cardiac parasympathetic nerve CHAT and VACHT,improving the damaged cardiac parasympathetic nerve,effectively stimulate the expression of myocardial M3R, activative MEK1/2.4 weeks aerobic exercise significantly improving the structure of the damaged heart muscle tissue of rats,reduce the degree of myocardial fibrosis,reduce myocardial infarction size, effective improve cardiac function;Eight weeks of continuous and intermittent motion can significantly reduce the collagen volume percentage (CVF), inhibit excessive proliferation of collagen, the effect of two kinds of exercise there was no significant difference,The effect of intermittent movement to the promotion of cardiac function continuous movement is more significant.4 weeks aerobic exercise can effectively reduce the myocardial cell apoptosis, especially in pathological heart more prominent.Aerobic exercise inhibit myocardial cell apoptosis, may be by raising M3R, activation of MEK1/2.8 weeks of continuous and intermittent movement can promote the expression of myocardial M3R,significant activation of MEK1/2,inhibit myocardial cell apoptosis, there was no significant differences between two kinds of movement. |
