Structural and biomechanical alterations in rabbit thoracic aortas are associated with the progression of atherosclerosis

Abstract

BackgroundAtherosclerosis is a diffuse and highly variable disease of arteries that alters the mechanical properties of the vessel wall through highly variable changes in its cellular composition and histological structure. We have analyzed the effects of acute atherosclerotic changes on the mechanical properties of the descending thoracic aorta of rabbits fed a 4% cholesterol diet.MethodsTwo groups of eight male New Zealand White rabbits were randomly selected and fed for 8 weeks either an atherogenic diet (4% cholesterol plus regular rabbit chow), or regular chow. Animals were sacrificed after 8 weeks, and the descending thoracic aortas were excised for pressure-diameter tests and histological evaluation to examine the relationship between aortic elastic properties and atherosclerotic lesions.ResultsAll rabbits fed the high-cholesterol diet developed either intermediate or advanced atherosclerotic lesions, particularly American Heart Association-type III and IV, which were fatty and contained abundant lipid-filled foam cells (RAM 11-positive cells) and fewer SMCs with solid-like actin staining (HHF-35-positive cells). In contrast, rabbits fed a normal diet had no visible atherosclerotic changes. The atherosclerotic lesions correlated with a statistically significant decrease in mean vessel wall stiffness in the cholesterol-fed rabbits (51.52 ± 8.76 kPa) compared to the control animals (68.98 ± 11.98 kPa), especially in rabbits with more progressive disease.ConclusionsNotably, stiffness appears to decrease with the progression of atherosclerosis after the 8-week period.

The impact of plaque type on strut embedment/protrusion and shear stress distribution in bioresorbable scaffold

“…26 The stiffness of the vessel wall increases from lipid-rich atheromas to fibrotic and fibrocalcific lesions. 27,28 In the present study, as expected, the polymeric struts penetrated deeper in lipid-rich atheromatous plaques than fibrous and fibrocalcific plaques, due to the viscoelastic properties of these plaque types.…”

Features of atherosclerosis of common carotid arteries among black Kenyans

“…Their increased number is caused by stimulation of their proliferative activity (OREKHOV, ANDREEVA, MIKHAILOVA et al, 1998;ZHDANOV, 1998) and migration of muscle cells from the tunica media (LIBBY, 2006). Distintegration of IEL occurs in advanced atherosclerosis (WONG and SCHREIBER, 1996;KWON, KIM, HONG et al, 1998;KONIARI, MARRILAS, PAPADAKI et al, 2011). Medial degeneration is caused by chronic apoptosis of vascular smooth muscle cells which accelerates atherogenesis and progression of atherosclerosis in the established plaques (CLARKE, LITTLEWOOD, FIGG et al, 2008).…”

Transauricular balloon angioplasty in rabbit thoracic aorta: a novel model of experimental restenosis

“…It should be noticed the safety of both transauricular balloon angioplasty and atherogenic diet with regard to the induction and progression of atherosclerosis. Especially, we used a non-commercial and easy manufactured atherogenic diet consisting of standard rabbit chow enriched with 4% cholesterol [ 13 ], without any additional atherogenic components, such as palm oil [ 14 ], peanut oil [ 15 ], high fat coconut oil [ 16 ], high fat corn oil [ 17 ], and lard combined with either yolk powder or peanut oil [ 18 , 19 ]. Interestingly, the normal renal and liver function of balloon injured hyperlipidaemic animals confirms the absence of complications with percutaneous transauricular angioplasty, suggesting a safe alternative non-commercial atherogenic diet together with a minimally invasive restenosis model.…”