title: Effects of inflammatory cytokines on vascular tone.
abstract: OBJECTIVE
  To assess the direct effects of the inflammatory cytokines interleukin-2 (IL-2), interleukin-6 (IL-6) and interleukin-8 (IL-8) on vascular smooth muscle contraction.
  
  
  METHODS
  Smooth muscle contractility was studied in the thoracic aorta isolated from male Sprague-Dawley rats. Syntheses of cAMP and nitric oxide (NO) were investigated in cultured rat vascular smooth muscle cells (VSMC).
  
  
  RESULTS
  Pretreatment of the rings with IL-6 (10 ng/ml) for 180 min caused a significant inhibition of their contraction in response to 10(-5) M phenylephrine, wile Il-2 (10 ng/ml) and IL-8 (100 ng/ml) showed no significant effect on the contraction. The inhibitory effect of IL-6 exhibited a dose-dependency (0.1 approximately 10 ng/ml). In cultured rat VSMC, synthesis of cAMP was increased time-dependently by IL-6, while IL-2 and IL-8 failed to show any significant effects. IL-2, IL-6 and IL-8 did not affect the production of nitrite, a stable metabolite of NO, by VSMC.
  
  
  CONCLUSIONS
  IL-6, but not IL-2 and IL-8, is a potent inhibitor of vascular contraction, which effect is mediated through the increased cAMP synthesis.
authors.affiliation: Department of Cardiology, Jichi Medical School, Tochigi, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Ohkawa
authors.forename: U
authors.initials: U
authors.lastname: Ikeda
authors.forename: T
authors.initials: T
authors.lastname: Kanbe
authors.forename: K
authors.initials: K
authors.lastname: Kawasaki
authors.forename: K
authors.initials: K
authors.lastname: Shimada
mesh_terms: D000818:Animals; D001011:Aorta; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000096:biosynthesis; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D016209:Interleukin-8 / Q000494:pharmacology; D007378:Interleukins / Q000494:pharmacology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014662:Vasoconstrictor Agents / Q000494:pharmacology
chemical_list: D007376:Interleukin-2; D015850:Interleukin-6; D016209:Interleukin-8; D007378:Interleukins; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D009569:Nitric Oxide; D000242:Cyclic AMP