• Much interest has focused recently on the important role played by the smooth muscle
cell in the pathogenesis of atherosclerosis. This is because it is the smooth muscle cell of
the intimal and subintimal region which is involved early and to a marked degree by the
lipid deposits.
The eye provides a model system with three unique advantages: (1) the iris is rich in smooth
muscle cells which are well localized; (2) lipid deposits in the eye can be easily seen and their
progression can be followed visually; (3) certain experimental modifications can be readily
introduced into the model system during life. For example, the eye can be sympathetically
denervated. This deprives smooth muscle cells of the levator and iris dilator muscles of locally
released norepinephrine. It is increasingly recognized that norepinephrine exerts a regula-
tory effect on lipid metabolism.
1971;2;23-34 Stroke (Stroke is published by the American Heart Association)
ARMSTRONG JAMES AUSTIN, WILLIAM ROBERTS, HANS NEVILLE and DONALD