[Studies on the blood pressure effects of various high doses of angiotensin II in depot form in rats under defined conditions].

Daily s.c. injections of 0.02--10.0 mg angiotensin in depot form for 14 days caused in rats, under defined conditions, pronounced dose-dependent effects, with an unusual tolerance to the drug being observed. The behaviour of the systolic and diastolic blood pressure and heart rate allowed to define 4 dose ranges. In the lowest dose range of 0.02 mg angiotensin-II a lasting borderline hypertension with only straight-line changes of diastolic blood pressure and bradycardia were observed. The doses of 0.15--1.25 mg angiotensin-II caused a continual blood pressure rise and led, between day 4 and 6 of the experiment, to a pronounced lasting resistance high-pressure without appreciable changes in heart rate. The strongest resistance high-pressure, which occurred as early as on day 3, with pronounced tachycardia was achieved with a dose of 2.5 mg angiotensin-II. Higher doses produced pronounced tachycardia but no significant effects on blood pressure. The varying dose-dependent effects of depot angiotensin are discussed, and the possibility is pointed out to study by the angiotensin-II hypertension model various mechanisms of a long-time hypertensive dysregulation.