title: Ang II enhances noradrenaline release from sympathetic nerve endings thus contributing to the up-regulation of metalloprotease-2 in aortic dissection patients' aorta wall.
abstract: OBJECTIVE
  To test the hypothesis that angiotensin II (Ang II) could enhance noradrenaline (NA) release from sympathetic nerve endings of the aorta thus contributing to the up-regulation of matrix metalloproteinase 2 (MMP-2) during the formation of aortic dissection (AD).
  
  
  METHODS
  Ang II, NA, MMP-2, MMP-9 of the aorta sample obtained during operation from aortic dissection patients were detected by High Performance Liquid Chromatography and ELISA and compared with controls. Isotope labelling method was used to test the impact of exogenous Ang II and noradrenaline on the NA release and MMP-2, MMP-9 expression on Sprague Dawley (SD) rat aorta rings in vitro. Two kidneys, one clip, models were replicated for further check of that impact in SD rats in vivo.
  
  
  RESULTS
  The concentration of Ang II, MMP-2, 9 was increased and NA concentration was decreased in aorta samples from AD patients. Exogenous Ang II enhanced while exogenous NA restrained NA release from aortic sympathetic endings. The Ang II stimulated NA release and the following MMP-2 up-regulation could be weakened by Losartan and chemical sympathectomy. Beta blocker did not influence NA release but down-regulated MMP-2. Long term in vivo experiments confirmed that Ang II could enhance NA release and up-regulate MMP-2.
  
  
  CONCLUSIONS
  AD is initiated by MMP-2 overexpression as a result of increased NA release from sympathetic nervous endings in response to Ang II. This indicates an interaction of RAS and SAS during the formation of AD.
authors.affiliation: Department of Cardiothoracic Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China ; Department of Cardiothoracic Surgery, Xiangyang Central Hospital, Xiangyang, Hubei Province, China.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Hu
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Wang
authors.forename: Hongbing
authors.initials: H
authors.lastname: Wu
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Yang
authors.forename: Wanli
authors.initials: W
authors.lastname: Jiang
authors.forename: Luocheng
authors.initials: L
authors.lastname: Li
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Hu
mesh_terms: D000320:Adrenergic Fibers / Q000378:metabolism*; D000784:Aortic Dissection / Q000378:metabolism*; D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D001011:Aorta / Q000378:metabolism* / Q000473:pathology; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007553:Isotope Labeling; D019808:Losartan; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000804:Angiotensin II; D020778:Matrix Metalloproteinase 2; D019808:Losartan; D009638:Norepinephrine