Apparently high plasma angiotensin II levels in patients with essential hypertension treated by converting enzyme inhibition

Abstract

Plasma angiotensin I and II (AI and All) were measured in 13 patients with essential hypertension before and during chronic treatment with enalapril (MK 421) and in seven subjects during an acute study. Two techniques were used for simultaneous extraction of AI and All. Despite appropriate correction for cross-reaction of AI with the All antibody, one of the techniques gave consistently higher All and lower AI levels in plasma of subjects treated with enalapril. The possibility of in vitro conversion of AI into All-immunoreactive material during the purification or the radioimmunoassay steps should be considered. The use of the alternative technique is proposed for simultaneous processing of blood samples for AI and AIL

Key Words:

• angiotensin I
• enalapril
• MK 421