[Deleterious action of adrenaline on the endothelial lining of the vessels]

Perfusion of the aorta of anesthesized rabbits with medium 199 containing adrenaline at a concentration of 10(-6)-10(-4) M results in multiple morphological damages of the endothelial lining: contraction of endotheliocytes with the dilation of intercellular borders, appearance of areas of swelling (from a diffuse edema of single cells up to massive swelling of several hundred cells). The surface of the deendothelized aorta was greater at the highest dose of adrenaline. Inclusion into the perfusate of adrenaline blockers, such as phentolamine and propranolol at a concentration of 10(-5) M prevented endothelial constriction and edema. Similar focal swelling in the intima of aorta and coronary arteries was found in children dying from grave stress (trauma, asphyxia). The data obtained indicate that adrenaline after its therapeutic intravenous or local use may exert a direct damaging effect on the vascular endothelium.