DOES NITRIC-OXIDE REGULATE SMOOTH-MUSCLE PROLIFERATION - A CRITICAL-APPRAISAL

Smooth muscle proliferation is involved in the pathogenesis of atheros clerosis, restenosis after angioplasty and vein graft failure due to n eointimal hyperplasia. Nitric oxide (NO) inhibits smooth muscle cell g rowth in vitro and experimental neointimal hyperplasia in vivo, sugges ting a role for NO as a regulator of smooth muscle cell proliferation. NO is also involved in the control of numerous other vascular functio ns including platelet and inflammatory cell adhesion, vascular reactiv ity and endothelial permeability. This review critically examines the experimental and clinical evidence that supports a role for NO as a mo dulator of smooth muscle cell proliferation, with an emphasis on the m ultiple mechanisms by which NO acts on vascular lesions.