Effect of Adrenaline and Noradrenaline on “Silicone-like Property” of Blood Vessels

Abstract

Using the direct observation technique in situ of mesenterial blood vessels of rabbits under the microscope, the intravenous administration of a small amount of adrenaline in a dose like 0.1, 1.0, 10.0μg per kg was found to induce a transient damage to the “silicone-like property” of blood vessels, i.e. a transient swelling and stickiness of endothelial cells to platelets and leucocytes often forming platelet or platelet-leucocyte thrombi. Such evidences were repeatedly produced in the same animal by successive administration and were cinematographed. In accordance with these evidences the number of circulating platelets decreases immediately, i.e. 5-30 minutes after the injection of 0.1-1.0μg per kg of adrenaline and at the same time the blood coagulation time was shortened. In man the intravenous injection of 0.1μg per kg of adrenaline was found to induce similar changes as in rabbits, i.e. immediate and transient decrease in the number of circulating platelets and abrupt and transient shortening of the blood coagulation time. On the other hand the intravenous administration of noradrenaline in the same dose in man and rabbit was found to be less effective in regard to the above-mentioned effects.