title: [Interleukin-2 induced endothelium-dependent relaxation of rat thoracic aorta].
abstract: Interleukin-2 (IL-2) therapy often results in potentially life-threatening side effects including hypotension. However, the mechanism has not been completely elucidated. In order to determine whether IL-2 modifies vascular tone, we investigated the effect of IL-2 on rat thoracic aorta rings and the underlying mechanisms. Effects of IL-2 on the contraction of high KCl and phenylephrine (PE) preconstricted rat thoracic aorta with or without endothelium were determined by organ bath technique. To explore the mechanism, nitric oxide synthase inhibitor L-N(G)-nitroarginine methyl ester (L-NAME), guanylyl cyclase inhibitor methylene blue, and cyclooxygenase inhibitor indomethacin were used. IL-2 (10-1000 U/ml) caused concentration-dependent relaxation of aorta rings preconstricted with PE (10 micromol/L) in endothelium-intact rings, but had no effect on KCl (120 mmol/L) preconstricted rings. Removal of the endothelium, or pretreatment with L-NAME (0.1 mmol/L) or methylene blue (10 micromol/L) or indomethacin (10 micromol/L), inhibited the relaxation of IL-2. The results indicate that the relaxation by IL-2 in rat aorta ring is endothelium-dependent and is possibly mediated by the NO-guanylyl cyclase pathway and cyclooxygenase-dependent pathway.
authors.affiliation: Department of Physiology, Zhejiang University School of Medicine, Hangzhou 310031.
authors.forename: Chun-Mei
authors.initials: CM
authors.lastname: Cao
authors.forename: Song
authors.initials: S
authors.lastname: Ye
authors.forename: Hu
authors.initials: H
authors.lastname: Yu
authors.forename: Qing-Sheng
authors.initials: QS
authors.lastname: Xu
authors.forename: Zhi-Guo
authors.initials: ZG
authors.lastname: Ye
authors.forename: Yue-Liang
authors.initials: YL
authors.lastname: Shen
authors.forename: Yuan
authors.initials: Y
authors.lastname: Lu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xia
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000502:physiology; D004730:Endothelium, Vascular / Q000187:drug effects; D045462:Endothelium-Dependent Relaxing Factors / Q000494:pharmacology*; D006162:Guanylate Cyclase / Q000378:metabolism; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000494:pharmacology*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D045462:Endothelium-Dependent Relaxing Factors; D007376:Interleukin-2; D014665:Vasodilator Agents; D009569:Nitric Oxide; D011451:Prostaglandin-Endoperoxide Synthases; D006162:Guanylate Cyclase; D019331:NG-Nitroarginine Methyl Ester