Abstract: Vascular function and structure is maintained or improved by long term administration of physiologically acceptable compounds which enhance the level of endogenous nitric oxide or other intermediates in the NO induced relaxation pathway in the host. Alternatively, or in combination, other compounds may be administered which provide for short term enhancement of nitric oxide, either directly or by physiological processes.

Abstract: Vascular function and structure is maintained or improved by long term administration of physiologically acceptable compounds, namely L-arginine, L-lysine, physiologically acceptable salts thereof, and polypeptide precursors thereof, which enhance the level of endogenous nitric oxide or other intermediates in the NO induced relaxation pathway in the host. In or in combination, other compounds, such as B.sub.6, folate, B.sub.12, or an antioxidant, which provide for short term enhancement of nitric oxide, either directly or by physiological processes may be employed.

Abstract: Atherogenesis and restenosis are treated by long term administration of physiologically acceptable compounds which enhance the level of endogenous nitric oxide or other intermediates in the NO induced relaxation pathway in the host. Alternatively, or in combination, other compounds may be administered which provide for short term enhancement of nitric oxide, either directly or by physiological processes. In addition, cells may be genetically engineered to provide a component in the synthetic pathway to nitric oxide, so as to drive the process to enhance nitric oxide concentration, particularly in conjunction with the administration of a nitric oxide precursor.