The blockade of the reinforcing effects of angiotensin-II on hemodynamic parameters in rats with experimental diabetes mellitus

Diabetes mellitus (DM) causes not only carbohydrate metabolism, but and disorders of the cardiovascular system, resulting in developing hypertension. It is known that in the regulation of hemodynamics the renin-angiotensin system plays an important role, the effector peptide of which is angiotensin II (A-II) causes hypertension and increases the heart rate (HR). In this work we studied the change in systolic blood pressure (SBP) and HR under the action of A-II in rats with experimental autoimmune type 1 DM. Autoimmune diabetes in Wistar rats was induced by injections of streptozotocin. Two weeks after the third injection, SBP and HR were measured in animals. The day before the start of the experiment the blood glucose level was detected. The results showed the absence of hypertensive properties of A-II and its reinforcing effect on HR in rats with autoimmune diabetes, indicating diabetic hyperglycemia as the main factor in the ineffectiveness of the action of A-II on hemodynamic parameters. It can be assumed that the significant increase of blood glucose level in condition of autoimmune diabetes type 1 DM occurs specific desensitization of receptors to A-II in the central and peripheral structures governing the SPB and HR, i.e., the blockade of the physiological action of this peptide.