Morphology Changes of Collagen Fibers in Rats Heart in Electronmicroscope under Different Exercise Loads

Objective:To observe the changes of collagen fibers in rats' cardiac muscle(CM) in electron microscope under different exercise loads.Methods: Thirty-six rats are divided into control group(C group),normal swimming group(NS group) and overload group(O group).Three groups are given normal,middle and overload swimming training respectively for 8 weeks.Then all rats are killed by decapitation,and taken out the antetheca and papillary muscle of left ventricle,and the changes of collagen fibers are observed through transmission and scanning electron microscope.Result: In control group,crude fibers,small fibers and microfilament of collagen fibers can be seen,and the cardiac muscle architectonic is integrated.In normal swimming group,the crude fibers much increase in muscle bundle blank and muscle bundle inner.And the bulk of cardiac muscle cell slightly increases,the number of mitochondrion increases.In overload group,the crude fibers remarkably increase in muscle bundle blank,and the cardiac muscle architectonic is destroyed.Conclusion: Overload training can lead to the crude fibers of cardiac muscle cell increasing,and it may be lead to broaden function and retracted function depressing.