Abstract 5059: Inhibition of Angiotensin II and Recruitment of Endothelial Progenitor Cells by Lactotripeptide Administration Ameliorates Vascular Endothelial Cell Function in Elderly Women
2 tripeptides in sour milk, valine- and isoleucine- proline-proline, were referred to lactotrip-eptide (LTP). LTP is an inhibitor of angiotensin-converting enzyme and has an antihypertensive effect. The impairment of endothelial function after menopause in females causes the increase in arterial stiffness and calcification, resulting in cardiovascular diseases such as coronary heart disease and stroke. Then, we hypothesized that 2-month ingestion of LTP could prevent vascular endothelial impairment in post-menopausal women through the anti-inflammatory effects and anti-renin angiotensin system. 33 post-menopausal women completed a 2-month ingestion of LTP (6.8 mg/day) or placebo intervention program. We measured number of endothelial progenitor cells (CD34, CD133, and KDR positive) in peripheral blood by flowcytometric analysis before and after the program. We also examined resting peripheral blood flow by Doppler blood flowmeter and flow-mediated dilation (FMD) on reactive hyperemia at brachial artery. Peripheral EPCs after LTP intervention was 2-fold increased compared to both baseline and placebo group. FMD was significantly elevated in LTP group by 44% compared to baseline and 11% to placebo group. Resting peripheral blood flow was significantly increased and blood pressure was significantly decreased in LTP group compared to baseline and placebo group. Plasma angiotensin II concentration in LTP group showed a significant decrease by 63% compared to baseline, not in placebo group. We demonstrated that LTP ingestion improved the impaired endothelial function in elderly women, through decreased plasma angiotensin II and increased peripheral EPCs.