In the article the results of research of the renin-angiotensin system features of influence on the vascular tone change dynamics during performing operations with artificial blood circulation are presented. The angiotensin-ІІ study in the greater circulation peripheral blood, during conducting artificial blood circulation, showed that its level in peripheral arteries has increased in comparison with tests from the arterial pathway of oxygenator, that in its turn testifies to excessive activation of local vascular component of RAS.
