Effects of swimming on the development of atherosclerosis in mice.

Objective: To investigate the effects of swimming on the formation of atherosclerotic lesions and the corresponding mechanism.

Methods: 20 ApoE-deficient young male mice of SFP grade were assigned equally into two groups: atherosclerosis group and swimming group. Atherosclerosis models were established by feeding with high cholesterol diet. Swimming exercise was performed at a frequency of 90 min per day, 6 days per weeks for 10 weeks. The weight index, histologic changes of aorta area, blood lipid levels, expression levels of eNOS, tNOS and iNOS, expression levels of MMP-9 and MMP-14, inflammatory factor levels, and oxidative stress status were compared between the two groups.

Results: Compared to the atherosclerosis group, the plaque area, plaque rupture rates, and vulnerable index in the aorta of the swimming group were significantly less and the fibrous cap thickness was greater. The weight of mice and serum lipid levels in the swimming group were superior. In addition, in contrast to atherosclerosis group, mRNA expression levels of eNOS, tNOS, iNOS, and SOD in the swimming group were signifiantly elevated, while the levels of MMP-9, MMP-14 and MDA, and serum levels of IL-6, Lp-PLA2, and TNF-α were significantly decreased.

Conclusion: Swimming exercise significantly decreases the development of atherosclerotic plaque in ApoE-deficient mice, possibly due to a reduction in the expression of blood lipid, MMP-9, MMP-14, MDA, IL-6, Lp-PLA2, and TNF-α and elevation in the expression of eNOS, tNOS, iNOS, and SOD.