The Effect Of Aerobic Endurance Exercise And Diet Adjustment On The Myocardial Collagen Network And The Expression Of Lysyl Oxidase

ObjectiveThrough a high-fat diet to establish obese rats model, to observe the remodeling ofmyocardial Collagen network and the expression of lysyl oxidase(LOX) after aerobicendurance exercise, diet adjustment, aerobic exercise combined with diet adjustmentthree interventions, to discuss the effect of the three interventions on myocardialCollagen network and the expression of lysyl oxidase, providing probable theory basisand mechanism to improve cardiac remodeling for obese individuals.methods72clean and health male SD rats (8weeks of age),after one-week adaptivefeeding, randomly divided into control group(C, n=10), fed with standard diet, otherrats are fed with high-fat diet(add10%lard,15%sucrose,0.2%cholesterol and0.2%egg yolk powder on the basis of normal feed) for12weeks,successfully establish theobese model.Then obesity rats were randomly divided into four groups:1)Quiet withhigh-fat fed(HS, n=10),2)Exercise with high-fat fed(HE, n=10),3)Quiet with normaldiet fed(NS, n=10) and4)Exercise with normal diet fed(NE, n=10).The group C、HS、NS remained sedentary while the group HE、NE underwent aerobic enduranceexercise for8weeks(20m/min,60min,6d/weeks). After intervention, Hydroxyprolinekit detect the degree of myocardial fibrosis, immunohistochemical staining toobserveⅠ and Ⅲ collagen fibers, Western Blotting detectthe expression of LOX.Result(1)After12weeks of high-fat fed, the body weight of the group M wassignificantly higher than the group C(553.73±31.46vs471.7±28.8, P<0.01). After8weeks of the intervention, the weight of the group NS increased and has no significantcompare with the group HS(P>0.05), but the group HE and group NE has significantdecreased compare with the group HS(P<0.01), the group NE has decreased most.(2)After eight weeks intervention, myocardial total hydroxyproline contentsignificantly increased in HS group than the group C(P <0.05), there was no significantdifference between NS group and HS group (P>0.05), compared with HS group,myocardial total hydroxyproline content in HE group and NE group were significantlyreduced (P <0.05), and NE group reduced more (P <0.01); myocardial cross-linkingcollagen part hydroxyproline content, compared with the C group,HS group wassignificantly increased (P <0.01), there was no significant difference between NS groupand HS group(P>0.05), compared with the control group, HE group and NE groupwere significantly reduced (P <0.01). (3)After eight weeks intervention, immunohistochemistry showed that bothⅠ andⅢ collagenexpression levels in HS group were significantly higher than the controlgroup (P <0.01), NE group were significantly higher than HS group (P <0.01), therewas no significant difference between HS group and NS group; Ⅰ collagenexpressionlevels, HE group were significantly higher than the HS group (P <0.05), Ⅲcollagenlevels, HE group were significantly higher than the HS group (P <0.01).(4)After eight weeks intervention, Western Blotting showed that there was nosignificant difference between HS group and C group in myocardial Mature-LOXexpression(P>0.05), contrary Pro-LOX expression had a significant reduction in HSgroup (P <0.01); myocardial Pro-LOX, Mature-LOX expression was no significantdifference in NS group compared with HS group (P>0.05); compared with HS group,myocardial Pro-LOX expression and Mature-LOX expression in HE group and NEgroup were significant reduced (P <0.05); Mature-LOX expression reduced more(P<0.01).Conclusion(1)After twelve weeks high fat diet, SD rats can establish obesity model,appropriate aerobic endurance exercise and resume normal diet can effectively controlweight, and aerobic exercise together with resume normal diet intervention appearedmore effective.(2)Type Ⅰand Ⅲ collagen fiber in obesity rat myocardium were hyperplasia,and had fibrosis tendencies. Aerobic exercise can reduce type Ⅰand Ⅲ collagenfiber, simply return to normal diet for improving myocardial fibrosis was ineffective.(3)Myocardial collagen cross-linking was seriously in obese rats, aerobicexercise can reduce the expression of Pro-LOX and Mature-LOX to decreasemyocardial collagen cross-linking, thus decreasing myocardial fibrosis. and resumenormal diet alone was no significant for altering myocardial Pro-LOX, Mature-LOXexpression levels, thus improving myocardial fibrosis.