Nitric oxide-associated relaxing effects of adrenomedullin in rat aorta

✍ Scribed by Kazuki Matsunaga; Takanori Iwasaki; Yukio Yonetani; Kazuo Kitamura; Tanenao Eto; Kenji Kangawa; Hisayuki Matsuo

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 402 KB
• Volume: 38
• Category: Article
• ISSN: 0272-4391
• DOI: 10.1002/(sici)1098-2299(199605)38:1<62::aid-ddr8>3.0.co;2-j

✦ Synopsis

The relaxing effect of adrenomedullin (AM) and that associated with nitric oxide (NO) were investigated in rat isolated aorta. The relaxing effect produced by AM was almost completely inhibited by the removal of endothelium and by treatment with the NOS inhibitor fl-nitro-L-arginine methyester (L-NAME) and hemoglobin but not by indomethacin. Thus the relaxing effect by AM was entirely dependent of endothelial NO synthesis but not of prostaglandins. The cGMP content in t h e AM-treated relaxed aorta did not change while the cAMP content significantly increased. These findings suggest that the relaxing effects produced by AM in rat aorta primarily relate to an increase in cAMP as well as cGMP maintained by the stimulation of NO spontaneously released from endothelium but not by cGMP resulting from enhanced NO release. There may be some synergistic mechanism between cAMP and NO-cGMP systems in the relaxing effect of AM in rat isolated aorta. o 19% Wiley-Liss, Inc.