title: Enhanced vascular contractility and diminished coronary artery flow in rats made hypertensive from diet-induced obesity.
abstract: OBJECTIVE
  To determine whether obesity-induced hypertension was associated with alterations in vascular contractility and/or cardiac function.
  
  
  METHODS
  Male Sprague-Dawley rats were fed either a low fat (LF; 11% kcal as fat) or a moderately high fat (MHF; 32% kcal as fat) diet for 11 weeks.
  
  
  METHODS
  Body weight; mean arterial pressure; angiotensin peptides; mesenteric contractile response to phenylephrine (PE), potassium chloride (KCl), serotonin, angiotensin II (AngII), calcium chloride; baseline and isoproterenol-induced cardiac contractility; baseline and isoproterenol-induced coronary artery blood flow.
  
  
  RESULTS
  Rats fed the MHF diet segregated into obesity-prone (OP) and obesity-resistant (OR) groups. OP rats exhibited elevations in mean arterial pressure (MAP) and elevations in systemic concentrations of angiotensin peptides. Mesenteric arteries from OP rats exhibited a greater contractile response to PE, KCl and serotonin (5-HT). Heightened responses to PE persisted in arteries from OP rats even after normalization of the response to KCl. In contrast, the response of permeabilized mesenteric arteries to a maximal concentration of calcium was similar in rats from each group. Isolated perfused hearts exhibited similar baseline and isoproterenol-induced contractility in rats from each group. However, isoproterenol was unable to increase coronary artery blood flow in hearts from OP rats.
  
  
  CONCLUSIONS
  Enhanced vascular reactivity may contribute to obesity-induced hypertension, while reductions in coronary artery relaxation would impair the ability of the heart to respond to increased myocardial demand.
authors.affiliation: Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY 40536-0200, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Boustany-Kari
authors.forename: M
authors.initials: M
authors.lastname: Gong
authors.forename: W S
authors.initials: WS
authors.lastname: Akers
authors.forename: Z
authors.initials: Z
authors.lastname: Guo
authors.forename: L A
authors.initials: LA
authors.lastname: Cassis
mesh_terms: D000809:Angiotensins / Q000097:blood; D000818:Animals; D001794:Blood Pressure; D003331:Coronary Vessels / Q000503:physiopathology*; D004032:Diet / Q000009:adverse effects; D018752:Diet, Fat-Restricted; D006973:Hypertension / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008638:Mesenteric Arteries / Q000503:physiopathology; D009765:Obesity / Q000097:blood / Q000150:complications*; D009924:Organ Culture Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D014661:Vasoconstriction; D014664:Vasodilation; D015430:Weight Gain / Q000502:physiology
chemical_list: D000809:Angiotensins