Biphasic response of intimal prostacyclin production during the development of experimental atherosclerosis.

Feeding a cholesterol rich diet (0.3%) to rabbits for up to 10 weeks resulted in morphological changes of the vascular wall. Microscopic evaluation of the aorta revealed a lipid infiltration and an intimal thickening containing foam cells, which both became more pronounced as the cholesterol feeding was more prolonged. The intimal prostacyclin production showed a transient increase after 2 weeks, but was significantly decreased after 6 weeks of diet and remained at this low level during the rest of the experiment. No significant changes in formation of thromboxane B2 by the platelets could be observed, whereas the production of 12-HETE was enhanced.