Effect of human adrenomedullin on a canine tibial perfusion model in the absence of vascular endothelium

✍ Scribed by Teiji Kato; Allen T. Bishop; Michael B. Wood

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 640 KB
• Volume: 14
• Category: Article
• ISSN: 0736-0266
• DOI: 10.1002/jor.1100140616

✦ Synopsis

Abstract

The effect of human adrenomedullin was investigated using an ex vivo perfused canine tibial model in the absence of vascular endothelium. Adrenomedullin is a novel peptide with known vasodilator properties. In this model. a 0.1 ml bolus injection of 10^−5^ M of either acetylcholine or adrenomedullin decreased vascular resistance in tibial preparations precontracted with prostaglandin F~2α~ by 88.3 ± 3.0% and 92.8 ± 2.8%, respectively, in the presence of vascular endothelium. Conversely, a 0.1 ml bolus injection of 10^−5^ M acetylcholine produced a constrictor response after removal of vascular endothelium. A 0.1 ml bolus injection of 10^−5^ M adrenomedullin decreased the baseline perfusion pressure in a dose‐dependent manner for a duration of 20 minutes and also attenuated the pressor response to exogenous norepinephrine injection for at least 10 minutes compared with the control study (p < 0.05) in the absence of vascular endothelium. These data suggest that human adrenomedullin relaxes blood vessels in bone by a direct action on vascular smooth‐muscle cells. In addition, the attenuation effect of human adrenomedullin on pressor responses to exogenous norepinephrine injection is independent of vascular endothelium.