Dyslipoproteinaemia, signal transduction, and angiogenesis.

Hyperlipidaemic states are associated with endothelial cell dysfunction which may in part be related to the accumulation of toxic lipoprotein degradation products in artery walls. One effect of oxidized LDL and its products is to impair transmembrane signalling, a process that might alter responsiveness of endothelial cells to mitogens. Endothelial cell replication plays a pivotal role in the growth of pre-existing arterial channels and in the formation of new microvessels (angiogenesis). Experiments in intact rabbits indicate that endothelial replication associated with vascular growth is markedly impaired in the presence of hypercholesterolaemia, a defect that could play an important role in the pathophysiology of occlusive atherosclerotic disease.