title: Blockade of the renin-angiotensin system in small arteries and anticontractile function of perivascular adipose tissue.
abstract: OBJECTIVE
  In patients with obesity, there is increased inflammation with attendant oxidative stress in perivascular adipose tissue. This has functional consequences with loss of vasodilator adipokine bioavailability. Part of the inflammatory response is mediated by increased activation of the renin-angiotensin-aldosterone axis. Therefore, this study was designed to investigate whether angiotensin-converting enzyme inhibitors or angiotensin receptor blockers can improve the anticontractile function of perivascular adipose tissue.
  
  
  METHODS
  Segments of rat mesenteric small artery were dissected and mounted in a wire myograph and contracted to incremental doses of norepinephrine in the presence and absence of perivascular adipose tissue and in conditions of normal oxygenation or after hypoxia and incubated with captopril or telmisartan.
  
  
  RESULTS
  Vessels with perivascular adipose tissue contracted significantly less than arteries with perivascular adipose tissue removed under normal oxygenation conditions, indicating that perivascular adipose tissue exerts an anticontractile effect. Hypoxia induced a loss of this anticontractile effect which could be completely prevented with captopril or telmisartan.
  
  
  CONCLUSIONS
  The in-vitro creation of a hypoxic environment can simulate the loss of anticontractile perivascular adipose tissue function seen in vivo in obese patients, and this can be prevented using inhibitors of the renin-angiotensin cascade.
authors.affiliation: aInstitute of Cardiovascular Sciences, Faculty of Medical and Human Sciences, University of Manchester, UK bClinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
authors.forename: Claudia Agabiti
authors.initials: CA
authors.lastname: Rosei
authors.forename: Sarah B
authors.initials: SB
authors.lastname: Withers
authors.forename: Laila
authors.initials: L
authors.lastname: Belcaid
authors.forename: Carolina
authors.initials: C
authors.lastname: De Ciuceis
authors.forename: Damiano
authors.initials: D
authors.lastname: Rizzoni
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Heagerty
mesh_terms: D054392:Adipokines / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D001160:Arterioles / Q000187:drug effects*; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D005260:Female; D006801:Humans; D000860:Hypoxia; D066298:In Vitro Techniques; D007249:Inflammation / Q000378:metabolism; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects; D009638:Norepinephrine / Q000378:metabolism; D009765:Obesity / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D011921:Rats, Inbred WKY; D017207:Rats, Sprague-Dawley; D012084:Renin-Angiotensin System / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects*
chemical_list: D054392:Adipokines; D000806:Angiotensin-Converting Enzyme Inhibitors; D009638:Norepinephrine