Abstract:

Objective

To explore the effect of long-term enhanced external counterpulsation(EECP)on morphological damage of endothelium in the aorta of hypercholesterolemic pigs.

Methods

18 male infant pigs were randomly divided into 3 groups according to their diet:the normal control group(n=6),the hypercholesterolemic control group(n=6)and the hypercholesterolemic+EECP group(n=6).Porcine model of hypercholesterolemia was built up by feeding animals with high-cholesterol diet.After completion of EECP treatment for 36 hours on the hypercholesterolemic+EECP group，abdominal aorta were harvested from all animals.Sudan Ⅲfatty streak staining was applied to evaluate macropathological atherosclerotic lesions in aorta endothelium.At the same time,both scanning and transmission electron microscopes were employed to observe the changes of their endothelium in morphology.

Results

Sudan Ⅲstaining in aorta showed that the area percentage of macropathological atherosclerotic lesions was much lower in the hypercholesterolemic + EECP group (6.53%±0.81%)than that in the hypercholesterolemic control group (9.48%±2.28%), but still much higher than that in the normal control group(1.66%±0.18%)，P<0.05；The surface of endothelium in the normal control group was smooth, and endothelial cells arrayed regularly in streamline almost in equal size,attaching closely to matrix without smooth muscle cells proliferation and lipid infiltration in intima.In contrast,the endothelial cells of hypercholesterolemic pigs arrayed irregularly and desquamated markedly,which resulted in looser endothelial linkage;and smooth muscle cells invaded into intimal layer and proliferated, and foam cells could be found in intimal layer. In hypercholesterolemic pigs treated with EECP,slight intimal damage was found.

Conclusion

Long-termEECPimproves the morphological damage resulting from hypercholesterolemia,contributing to postponing atherogenesis and progression of the early atherosclerosis lesions.

Key words: Enhanced external counterpulsation, Hypercholesterolemia, Endothelium, Aorta