Epinephrine Effect on Arterial Endothelial Cells Observed by Scanning Electron Microscope

In 12 rabbits aortic specimens were sampled at several time-intervals after the one shot treatment of animals with 1μg/kg of epinephrine.The specimen from 2 animals taken 15 minutes after 1μg/kg epinephrine exhibited some irregularity of endothelial folds and a slight edematous swelling and elongation of intercellular long bridges. The specimens from 4 animals, taken 30 minutes after the same challenge with epinephrine, exhibited a definite irregularity of endothelial folds and the edematous swelling and elongation of intercellular long bridges. On the other hand in 6 animals sacrificed immediately thereafter or 5 or 10 minutes after the same challenge with epinephrine, the above mentioned changes were minimal or absent.The specimens from 2 animals, taken 30 minutes after the injection of 100μg/kg of epinephrine, exhibited a remarkable edematous swelling of intercellular long bridges.The specimens from 3 animals, received a drip infusion (1μg/ kg/min., for 15min.) exhibited the constricted feature of endothelial folds and a remarkable edematous swelling and elongation of intercellular long bridges.