Vitamin C increases the prostacyclin production and decreases the vascular lesions in experimental atherosclerosis in rabbits.

Feeding a cholesterol-rich diet (0.3%) to rabbits resulted in an intimal thickening and lipid infiltration of the aorta. The prostacyclin production by the vascular endothelium was significantly decreased, after a transient increase after 2 weeks of diet. The arachidonic acid metabolism in platelets was hardly changed. Addition of a low dose vitamin C (150 mg/day) to the cholesterol rich diet resulted in decreased lipid infiltration and intimal thickening and the transient increase of the prostacyclin production was postponed to the 4th week. Although this dose of vitamin C could not restore the decreased prostacyclin production observed after 6 weeks diet, a higher dose of vitamin C (600 mg/day), besides its beneficial effect on the lipid infiltration and the intimal thickening in the thoracic aorta, kept the intimal prostacyclin production at normal levels for at least 8 weeks.