Abstract
Nicotianamine has angiotensin converting enzyme (ACE) inhibitory activity, and exhibits an antihypertensive effect upon long-term administration in SHR. We isolated nicotianamine from several types of plant and devised a quick and simple assay system for nicotianamine in plants using the HPLC method. In the present study using Tsukuba hypertensive mice (THM), we investigated the influence of nicotianamine on the renin-angiotensin system (RAS). The THM is a hypertensive animal model prepared by introducing human renin and angiotensinogen genes into the C57BL/6 mouse. In THM, the cause of hypertension is a single factor, i.e. enhancement of the RAS. We measured nicotianamine concentration in the plasma of THM. It was confirmed that, after administration into the stomach, nicotianamine was absorbed from the intestine and detected in the blood. Consequently, the blood pressure decreased significantly for 6h after the administration of nicotianamine, and ACE activities in plasma, lung and kidney were decreased. It was suggested that the absorbed nicotianamine decreased the ACE activity and blood pressure.
