Milk casein-derived tripeptides, VPP and IPP induced NO production in cultured endothelial cells and endothelium-dependent relaxation of isolated aortic rings
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Tatsuhiko Hirota Atsuko Nonaka Akiko Matsushita Naoto Uchida Kohji Ohki Masanori Asakura Masafumi Kitakaze
- چاپ و سال / کشور: 2010
Description
Milk casein-derived tripeptides, valyl prolyl proline (VPP), and isoleucyl prolyl proline (IPP) inhibit angiotensin-converting enzyme (ACE) and both fermented milk and proteolytic hydrolysates of milk casein containing these peptides exert blood pressure-lowering effects in animals and humans. On the top of these results, we have recently reported that the hydrolysate of milk casein containing both VPP and IPP improved the vascular endothelial function of subjects with stage I hypertension, enforcing us to elucidate the mechanism of the improvement of endothelial dysfunction by these peptides. For this purpose, we examined the effect of VPP and IPP on induction of nitric oxide (NO) production using cultured vascular endothelial cells and isolated arterial vessels. When both VPP and IPP were added to the medium of cultured endothelial cells at final concentrations of more than 100 nmol/l, the NOx (NO2 and NO3) concentration in the medium was significantly higher than that of the control. Moreover, both VPP and IPP induced endotheliumdependent relaxation of isolated aortic rings, and these effects were inhibited by NO synthase inhibitors, K channel inhibitors, and bradykinin B2 receptor antagonists. These lines of results suggested that both VPP and IPP induced production of vasodilative substances including NO.
Heart Vessels DOI 10.1007/s00380-010-0096-y Received: 4 March 2010 / Accepted: 22 October 2010
