Reduced contractile function after balloon denudation of rat carotid arteries.

In rat carotid arteries isolated 2 weeks after balloon denudation, a significant neointima developed with little change in medial size. Associated with this neointimal hyperplasia was a marked decrease in contraction to various agents including angiotensins I and II, big endothelin-1, endothelin-1, norepinephrine, phenylephrine, and serotonin. Vasodilator responses to acetylcholine were significantly reduced. In contrast, vasodilator responses to nitroglycerin were unaffected. It is suggested that modulation of the neointimal cells to a more non-contractile phenotype may be responsible for the loss in contractile ability.