title: Perivascular Adipose Tissue: A Novel Regulator of Vascular Tone in the Rat Pregnancy.
abstract: Perivascular adipose tissue (PVAT) contributes to vasoregulation. The role of this adipose tissue bed in pregnancy has not been examined. Here, we tested the hypothesis that PVAT in pregnant rats decreases resistance artery tone. Mesenteric arteries from nonpregnant (NP) and late pregnant (LP) rats were exposed to phenylephrine (PHE) or KCl in the presence (+) versus absence (-) of PVAT. The LP PVAT(+) vessels showed a 44% decrease in sensitivity to PHE in the presence of PVAT. There was no attenuation of the contractile response to KCl when PVAT was present. The LP arteries perfused with LP or NP PVAT underwent vasodilation; unexpectedly, NP vessels in the presence of PVAT from LP rats sustained a 48% vasoconstriction. The PVAT attenuates vasoconstriction by a mechanism that involves hyperpolarization. The vasoconstriction observed when nonpregnant vessels were exposed to pregnant PVAT suggests pregnant vessels adapt to the vasoconstricting influence of pregnant PVAT.
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont College of Medicine, Burlington, VT, USA semann@uvm.edu.
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Mann
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont College of Medicine, Burlington, VT, USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Maille
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont College of Medicine, Burlington, VT, USA.
authors.forename: Darren
authors.initials: D
authors.lastname: Clas
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Vermont College of Medicine, Burlington, VT, USA.
authors.forename: George
authors.initials: G
authors.lastname: Osol
mesh_terms: D000273:Adipose Tissue / Q000098:blood supply* / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D005260:Female; D008638:Mesenteric Arteries / Q000187:drug effects / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D009924:Organ Culture Techniques; D010656:Phenylephrine / Q000494:pharmacology; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013152:Splanchnic Circulation / Q000187:drug effects / Q000502:physiology; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*
chemical_list: D010656:Phenylephrine
keywords: hyperpolarization; perivascular adipose tissue; phenylephrine; pregnancy; vasoregulation