ABSTRACT
<p><b>OBJECTIVE</b>To study the effects of enhanced external counterpulsation (EECP) on the vascular morphology, and endothelial function using experimentally induced hypercholesterolemic pigs.</p><p><b>METHODS</b>Thirty five male pigs were randomly divided into three groups: 7 normal control animals, 11 hypercholesterolemic animals, and 17 hypercholesterolemic animals receiving EECP. Serum cholesterol was measured. The coronary arteries and aortas were sampled for histopathologic and ultrastructural examination. The NF-kappaB protein expression of porcine coronary arteries was investigated by immunofluorescence.</p><p><b>RESULTS</b>Compared with the normal controls, serum cholesterol levels were significantly higher in the hypercholesterolemic animals with or without EECP. The plaque/intimal area ratio of the aorta decreased significantly in animals receiving EECP [(3.33 +/- 2.40)%, versus (12.03 +/- 7.12)% in those without EECP, P < 0.05]. Lipid deposition, endothelial damage and proliferation of smooth muscle cells were less severe in animals receiving EECP than those not. Moreover, activation and expression of NF-kappaB also decreased significantly (P < 0.05) in animals receiving EECP.</p><p><b>CONCLUSIONS</b>EECP improves the morphology and function of vascular endothelium, and retards the development and progression of atherosclerosis, likely through the inhibition of NF-kappaB signaling pathway.</p>