REDUCED CONTRACTILE FUNCTION AFTER BALLOON DENUDATION OF RAT CAROTID ARTERIES

In rat carotid arteries isolated 2 weeks after balloon denudation, a s ignificant neointima developed with little change in medial size. Asso ciated with this neointimal hyperplasia was a marked decrease in contr action to various agents including angiotensins I and II, big endothel in-1, endothelin-1, norepinephrine, phenylephrine, and serotonin. Vaso dilator responses to acetylcholine were significantly reduced. In cont rast, vasodilator responses to nitroglycerin were unaffected. It is su ggested that modulation of the neointimal cells to a more non-contract ile phenotype may be responsible for the loss in contractile ability.