Changes in blood glucose levels are paralleled by modification of normal activities of angiotensin II and angiotensin IV. Hypo- and hyperglycemia similarly reduced the hypertensive effect of angiotensin II and similarly distorted the initial hypotensive effect of angiotensin IV. Presumably, the adaptation and compensatory processes in the renin-angiotensin system under conditions of shifted homeostatic constants manifest by phenomena of external reintegration and redistribution of functions of its individual peptide components. This provides restructuring of the mechanisms of intra- and intersystemic organization of physiological functions under extreme conditions.