Endothelial changes following repeated effect of vasoconstrictive substances in vitro

Using perfusion method the reactivity of rabbit femoral and ear arteries was investigated following the administration of rising noradrenaline doses in four consecutive intervals. Progressive increase of vasoconstrictive activity of vessel segments was found. Results of histological examination showed a progressive de-endothelialization of perfused vessels. The loss of endothelium increased depending on time of action and on intensity of vasoconstrictive stimuli.