@entity1007 may render @entity731 plaques prone to rupture. To test this hypothesis, catheters with matrix-covered balloons were implanted into the aorta of @entity95 fed standard or 0. 5% @entity165 chow (n=70). In 1 month, fibrous plaques developed around the balloon. Time-dependent accumulation of @entity8557 and free @entity165 was detected in the plaques of the @entity165 -fed group only. The pressure needed to rupture the plaque by balloon inflation was used as an index of plaque strength. Three months after the catheter implantation, the breaking pressure was 2.1 times lower (P<0.05) in @entity165 -fed @entity95 . It was accompanied by collagen loss, as measured by plaque @entity720 content, but not with deficiency of collagen cross-linking. Sirius red staining showed preservation of collagen originally covering the balloon and accumulation of nascent collagen in the lesions of standard chow-fed @entity95 . In the @entity165 -fed group, both mature and new collagen underwent degradation predominantly in the plaque shoulders. Collagen breakdown was associated with local accumulation of foamy macrophages. Gel zymography demonstrated relative enhancement of gelatinolytic activity at 92 and 72 kDa, as well as caseinolytic activity at 57, 45, and 19 kDa in the lipid-laden plaques. Lipid accumulation in the plaque was also associated with a loss of smooth muscle cells, the cellular source of the collagen fibers. The remaining smooth muscle cells showed increased collagen synthesis, although it was insufficient to counterbalance collagen degradation and cell loss. Thus, we have obtained direct evidence that @entity1007 is accompanied by enhanced local collagen degradation, which is potentially responsible for @entity527 .

XXXX causes mechanical weakening of @entity95 atheroma : local collagen loss as a prerequisite of plaque rupture.

@entity527 :: ('MESH:D058225', 'Disease') :: ['plaque weakening'] @entity1007 :: ('MESH:D006937', 'Disease') :: ['Hypercholesterolemia', 'hypercholesterolemia'] @entity95 :: ('9986', 'Species') :: ['rabbits'] @entity720 :: ('CHEBI:18095', 'Chemical') :: ['hydroxyproline'] @entity731 :: ('MESH:D050197', 'Disease') :: ['atherosclerotic'] @entity8557 :: ('MESH:D002788', 'Chemical') :: ['cholesteryl esters'] @entity165 :: ('MESH:D002784', 'Chemical') :: ['cholesterol']
@entity1007 :: (MESH:D006937,Disease) :: ['Hypercholesterolemia']
