Antihypertensive Effects of Angiotensin Fragments in SHR

Abstract

When angiotensin fragments, Val-Tyr and Angiotensin III (ANG III), with potent ACE inhibitory activity were intravenously administered to spontaneously hypertensive rat (SHR), a significant reduction of diastolic blood pressure was observed. After incubation of ANG III with SHR plasma, four fragments with ACE inhibitory activity, Val-Tyr (ANG (3-4)) (IC₅₀=26.0μM), Ile-His-Pro-Phe (ANG (5-8)) (11.6μM), Tyr-Ile-His-Pro-Phe (ANG (4-8)) (457.5μM), and Val-Tyr-Ile-His-Pro-Phe (ANG (3-8)) (6.55μM), were confirmed to generate in SHR plasma. Compared the metabolic behavior of ANG II in SHR plasma with that in normotensive Wistar plasma, the initial degradation rate (3.07nmol/ml/min) in Wistar plasma was about 2-fold higher than that in the SHR one (1.75nmol/ml/min).