[In vitro model to investigate the effect of estrogens on neointima development after endothelial injury in the rabbit aorta].

Animal experiments are widely accepted in arterosclerosis research. Estrogens have lipid lowering properties and beneficial effects on the vasomotion. They act antiproliferative on those cells of the vascular wall which play a major role in lumen narrowing after vascular injury and in atherogenesis. The aim of the present study was to establish an organ culture model (rabbit aorta) to investigate post injury estrogen effects in the vessel wall. We chose the rabbit abdominal aorta which is the target organ in various animal experiments on this matter. The endothelial mono-layer was manipulated in a way that caused a measurable and reproducible post injury reaction (neointima formation). Then the effect of different estrogens (17beta-Estradiol, the phytoestrogens Genistein and Daidzein) on neointima development was investigated in male and female rabbit aortae. In equivalent dosages of 50 microg/ml all three estrogens inhibited the neointima formation significantly in male and female vessels. By the use of this organ culture model it was possible to show post injury effects of different estrogens in the vasculature while the consumption of animals was significantly reduced. Because 10 aortic segments could be taken from one aortic vessel, the number of animals that would have been necessary for an in vivo experiment could be reduced by the factor 10.