| 
Atherosclerosis and Thrombus Formation
Smooth Muscle Cell Migration and Proliferation
 The
smooth muscle cell is another major component -- and progenitor
-- of the fatty streak [Hajjar DP and Nicholson AC, 1995].
Along with macrophages, smooth-muscle cells (which normally
lie in the medial layer and are responsible for maintaining
vascular tone) proliferate in the intima during atherogenesis.
Proliferation of smooth muscle cells within
the intima makes up a substantial bulk of the atherosclerotic
lesion, which may rise several millimeters above the surface
of the surrounding intima. A number of molecular factors
may play a role in the proliferation and migration of smooth-muscle
cells. They include growth factors (eg, platelet-derived
growth factor, or PDGF, a polypeptide released from blood
platelets and endothelial cells that may attract smooth-muscle
cells to the intima and encourage them to divide), eicosanoids
(which can stimulate the hydrolysis of cholesteryl ester,
producing free cholesterol), certain cytokines (eg, tumor
necrosis factor, interleukin-1 and interferon), and nitric
oxide (which acts to dilate blood vessels) [Hajjar DP and
Nicholson AC, 1995].
|
Stroke Education
