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Effect Of Aerobic Exercise On The Level Of Basal Autophagy In Skeletal Muscle Of Spontaneously Hypertensive Rats And Its Mechanism

Posted on:2017-01-05Degree:MasterType:Thesis
Country:ChinaCandidate:X Q FengFull Text:PDF
GTID:2357330512469428Subject:Human Movement Science
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Object:Hypertension is a major risk factor for cardiovascular disease pathogenesis. Elliott M etal found that autophagy played an important role in the development and progression of hypertension, but what kind of change in the level of autophagy hypertension in rats, not very clear. The literature of Cui di and Qiushou-tao found that autophagy in obesity, aging and other chronic diseases, the level of autophagy in skeletal muscle showed a fall trend. If hypertensive rats autophagy levels drop,the movement as an mean of intervention, whether through up-regulation the level ofautophagy in skeletal muscle,improving the SHR ratskeletal muscle morphology and metabolism is not very clear.In this study, we built a 10 week aerobic exercise model, the foundation condition observation, exercise on hypertensive rats skeletal muscle autophagy start stage key protein Beclinl,autophagy bubble extension period key protein LC3 and autophagy lysosome fusion degradation stage of key protein P62 expression changes, To investigate the protective effect of exerciseon skeletalmuscle of SHR, to provide a experimental support for the prevention and treatment ofhypertension.Methods:The experimental study used 16 four weeks old specific pathogen free male (Wistar-Kyoto rats, WKY) and 20 SHR. WKY were randomly divided into rest group (WKY=7) and no weight loading swimming exercise group (WKY+E=9),after adaptive feeding for one week.SHR rats were randomly divided into rest group (SHR=9) and no weight loading swimming exercise group (SHR+E=11). The training time of the two groups of rats was selected in the dark period (18:00?20:00),its first day training time is 15min,subsequent increasing,until the six day training time increased to 90min,take a day off,after according to the 90min/d,6d/w,exercise program of weekly rest a day for 10 weeks.After the completion of the training,in 12-24hour, with a 5% of sodium pentobarbital anesthesia after the four groups of rats, gastrocnemius muscle of the left and right lower limbs of rats was rapidly removed and weighed in 6min.Every Friday regularly weighed and every evening regularly weighed feed weight. HE staining was used to observe the morphological changes of skeletal muscle in four groups of rats.The changes of SOD and MDA levels in skeletal muscle tissue of four groups were detected by MDA and SOD kit. Western blot was used to detect the expression of autophagy related protein Beclinl, LC3 and P62 in four groups of rats skeletal muscle.Results:1.The four groups of rats had no significant changes in body weight and daily diet in the five weeks, the body weight of the exercise group decreased significantly after sixth weeks. The exercise group of the average daily diet was significantly increased compared with the quiet group. Have statistical significance (p<0.05). The results showed that the body weight of exercise group was decreased, but food intake was increased.2.The results of gastrocnemius relative weight, WKY (4.698±0.3039) and SHR (3.571±0.3115) compared to the two groups, SHR gastrocnemius relative weight decreased significantly (p<0.05). The result showed that SHR rat skeletal muscle mass decreased. SHR(3.571±0.3115)and SHR+E(3.928±0.1995) compared to the two groups, WKY (4.698±0.3039) and WKY+E(5.124±0.2033) compared to the two groups, although two exercise groups of the relative weight of the gastrocnemius had a decrease, but no statistical significance (p>0.05)3.Skeletal morphology results showed, (1) the transverse plane of rats showed that in the 400×magnification, SHR rat's muscle cells appear nuclear center phenomenon, irregular shape of the muscle cell, muscle cell gap increased. SHR+E was improved in the muscle cells of SHR. Muscle nuclear of WKY were distributed the edge of the muscle cell, muscle cell arranged in a regular ordered. There was no significant change in the WKY+E and WKY. (2) The cross-sectional area of muscle fiber showed that WKY(7719±811.1) and SHR (4108±577.6) compared to the two groups, SHR rats muscle fiber cross-sectional area had a very significantly decreased (p<0.01). SHR (4108±577.6) and SHR+E(6500±482.4) compared to the two groups, SHR+E muscle fiber cross-sectional area had a increased significantly (p<0.05). WKY(7719±811.1) and WKY+E(9926±487.4) compared to the two groups, WKY+E muscle fiber cross-sectional area had a increased significantly (p<0.05). (3) Four groups of rat gastrocnemius muscle longitudinal section display, destruction of the spontaneous hypertensive rats muscle fiber morphology, increasing the distance between the muscle fibers nuclear distribution. After exercise, the muscle fibers of SHR+E rats were more compact than SHR, and narrowing of the myocytes gap. WKY, WKY+E muscle fiber part of the two groups of rats was contracting, and the nuclear of muscle was distributed in the edge of the muscle cell. Muscle wire ordered arrangement. The results showed that skeletal muscle morphology of SHR rats was significantly damaged and muscle fibers were degradded. After 10 weeks swimming, the skeletal muscle morphology of SHR rats was significantly improved.4.The results of skeletal muscle SOD and MDA showed, (1) Gastrocnemius muscle tissue T-SOD activity results showed that WKY (548.5±5.781) and SHR (413.6± 10.06) compared to the two groups, SHR group T-SOD activity had a very significantly reduced (p<0.01).SHR (413.6±10.06) and SHR+E (479.7±11.01) compared to the two groups, WKY (548.5±5.781) and WKY+E (601.0±17.34) compared to the two groups, the vitality of T-SOD of the gastrocnemius the two exercise groups significantly increased than the vitality of T-SOD of the gastrocnemius the two control quiet groups (p<0.05). (2) MDA content results showed that WKY (27.30±2.384) and SHR (40.61±10.09) compared to the two groups, the content of MDA in SHR rats was a very significantly increased (p<0.01).SHR (40.61±10.09) compared with SHR+E(29.22±2.055), the content of MDA in SHR+E rats was significantly increased (p<0.05).WKY (27.30±2.384) and WKY+E (26.32±2.866) two groups compared, although the content of MDA in WKY+E group rat had a decrease, but no statistical significance (p>0.05). The results showed that 10 weeks swimming exercise increased the levels of SOD and decreased MDA content in SHR rats.5.Western Blot results showed that(1) WKY(0.4283±0.1049) compared with SHR (0.3070+-0.1189), SHR gastrocnemius muscle tissue had a very lower expression of Beclinl (p<0.01). SHR (0.3070±0.1189) and SHR+E (0.4636+0.1362) compared to the two groups, SHR+E gastrocnemius muscle tissue Beclinl expression was a very significantly increased(p<0.01).WKY(0.4283±0.1049) and WKY+E(0.4995±0.09066) compared to the two groups, WKY+E group, the expression of Beclinl in the gastrocnemius muscle tissue had a increase, but there was no statistical significance (p>0.05). (2) WKY (0.3229±0.05376)and SHR (0.2818±0.04133) two groups compared, SHR rats gastrocnemius muscle tissue of LC3 ? protein expression significantly decreased (p<0.05). Compared with SHR (0.2818±0.04133) and SHR+E (0.3506±0.04364),SHR+E rats gastrocnemius muscle tissue of LC3 ? protein expression significantly increased (p<0.05). WKY (0.3229±0.05376) and WKY+E (0.4406±0.07123) compared to the two groups, WKY+E rats gastrocnemius muscle tissue of LC3 ? protein expression had a significantly increase (p<0.05). The results showed that 10 weeks swimming exercise made the level of autophagy of WKY,SHR groups rats significantly increased.(3) WKY(1.107±0.02328) and SHR(0.9143±0.1027) two groups compared, SHR rats gastrocnemius muscle tissue of LC3 ?/LC3 ? ratio decreased significantly (p<0.05). compared SHR(0.9143±0.1027) with SHR+E (1.163±0.05718), SHR+E rats gastrocnemius muscle tissue of LC3?/LC3 ? ratio increased significantly (p<0.05). WKY(1.107±0.02328) and WKY+E (1.278±0.08978) two groups compared, WKY+E rats gastrocnemius muscle tissue of LC3 ?/LC3 ? ratio increased significantly (p<0.05). The results showed that swimming exercise made the ratio of LC3 ?/LC3 ? of the WKY,SHR rats increase. (4) Compared WKY (0.3450±0.05079) with SHR (0.4659±0.03408), SHR, the expression of p62 in the gastrocnemius muscle tissue increased significantly (p<0.05). SHR (0.4659±0.03408) and SHR+E(0.3728±0.05377), two groups compared, SHR+E the expression of p62 in the gastrocnemius muscle tissue decreased significantly (p<0.05). compared WKY (0.345±0.05079) with WKY+E (0.3564±0.02842),WKY+E gastrocnemius muscle tissue have the higher expression of P62, but no significant difference (p>0.05). The skeletal muscle of SHR rats the protein expression levels of Beclinl,LC3 ? were decreased,p62 increased.The tatio of LC3 ?/LC3 ? decreased.After 10 weeks swimming, the skeletal muscle of SHR rats the protein expression levels of Beclinl, LC3 ? were increased, p62 decreased. The ratio of LC3 ?/LC3 ? increased.Conclusion:1.Morphology of SHR rat skeletal muscle damaged and oxygen free radical scavenging capacity decreased; Exercise improved the morphology of skeletal muscle and enhanced oxygen scavenging capacity.2.SHR rat the levels of skeletal muscle autophagy droped, exercise increased; The mechanism may be related to the movement increased the expression of skeletal muscle Beclinl, LC?, increasedthe ratio of LC3?/LC3 ?, decreased the expression of P62,...
Keywords/Search Tags:Swimming exercise, Hypertension, Skeletal muscle autophagy, Beclin1, LC3, P62
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