title: Perivascular adipose tissue and mesenteric vascular function in spontaneously hypertensive rats.
abstract: OBJECTIVE
  Perivascular adipose tissue of normotensive rats releases a transferable factor that induces relaxation by opening voltage-dependent K+ (Kv) channels. The relevance of these observations to hypertension is unknown.
  
  
  RESULTS
  We characterized mesenteric perivascular adipose tissue from 3-month-old Wistar Kyoto rats (WKY) and aged-matched spontaneously hypertensive rats (SHR). Mesenteric bed (MB) weight and MB total lipid content were lower in SHR than in WKY. Freshly isolated MB adipocytes were smaller in SHR. Plasma triglycerides, glycerol, nonesterified free-fatty acids, and cholesterol were also lower in SHR. Plasma and mesenteric leptin were correlated with the quantity of mesenteric fat. To study vascular function, the MB was cannulated and perfused at a constant 2 mL/min flow. The Kv channel blocker 4-aminopyridine (4-AP; 2 mmol/L) increased perfusion pressure less in SHR MB than WKY and was directly correlated with the mesenteric fat amount. In isolated mesenteric artery rings, 4-AP (2 mmol/L) induced a contractile effect that was attenuated in SHR compared with WKY. The anticontractile effects of perivascular fat were reduced in SHR mesenteric artery rings compared with WKY.
  
  
  CONCLUSIONS
  Differences in visceral perivascular adipose tissue mass and function may contribute to the increased vascular resistance observed in SHR.
authors.affiliation: Unidad de Cartografía Cerebral, Instituto Pluridisciplinar, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Gálvez
authors.forename: Javier
authors.initials: J
authors.lastname: de Castro
authors.forename: Diana
authors.initials: D
authors.lastname: Herold
authors.forename: Galyna
authors.initials: G
authors.lastname: Dubrovska
authors.forename: Silvia
authors.initials: S
authors.lastname: Arribas
authors.forename: M Carmen
authors.initials: MC
authors.lastname: González
authors.forename: Isabel
authors.initials: I
authors.lastname: Aranguez
authors.forename: Friedrich C
authors.initials: FC
authors.lastname: Luft
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Ramos
authors.forename: Maik
authors.initials: M
authors.lastname: Gollasch
authors.forename: Maria S
authors.initials: MS
authors.lastname: Fernández Alfonso
mesh_terms: D015761:4-Aminopyridine / Q000494:pharmacology; D017667:Adipocytes / Q000473:pathology; D000273:Adipose Tissue / Q000473:pathology* / Q000503:physiopathology*; D000818:Animals; D001808:Blood Vessels / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D048429:Cell Size; D006973:Hypertension / Q000235:genetics / Q000473:pathology* / Q000503:physiopathology*; D066298:In Vitro Techniques; D020738:Leptin / Q000097:blood / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000503:physiopathology; D026902:Potassium Channel Blockers / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013152:Splanchnic Circulation; D014661:Vasoconstriction; D014666:Vasomotor System / Q000503:physiopathology*
chemical_list: D020738:Leptin; D008055:Lipids; D026902:Potassium Channel Blockers; D015761:4-Aminopyridine