Arteriosclerosis in rabbits after balloon dilatation of the aorta

Abstract

We investigated the effects of balloon dilatation of the aorta of rabbits who had been fed a cholesterol enchriched diet or had been maintained on a standard chow. The luminal diameter, which was calculated as mean diameter of a circle bordered by the elastic interna, and the luminal stenosis were assessed in 16 segments of the aorta with an automatical computerized method. In both animal groups, in which the aorta was dilated four times with a balloon filled with constant volume from the aortic arch to the branching of the iliac vessels, atherosclerosis increased drastically in the abdominal aortic segments. Atherosclerosis was more pronounced in the cholesterol fed animals; the intimai proliferations of these animals contained a high number of foam cells. We conclude from our results: a) balloon dilatation can effect a proliferation of the intima. The development of the intimai hyperplasia obviously depends on the degree of the aortic injury, by which not only the endothelium but also the media could be affected. b) Addition of cholesterol to the diet exacerbates the effects of the balloon dilatation.

Zusammenfassung

Beginn und Progression einer Arteriosklerose können u. a. durch mechanische, wie Verletzungen des Endothels, und chemische Faktoren, z. B. Hypercholesterinämie, beeinflußt werden. Eine Deendothelialisierung der Aorta durch Ballondilatation löst bei Kaninchen und Ratten eine Reihe zellulärer Reaktionen aus [1, 3], in deren Folge sich innerhalb von Tagen eine hyperplastische Neointima entwickelt [4]. Wird Kaninchen nach der Ballondilatation mit Cholesterin angereichertes Futter verabreicht, so kommt es zu stärkeren Veränderungen verschiedener Enzyme als nach alleiniger Cholesterinfütterung [8].

supported by the SFB 320