title: [Modulation of iron on the vasodilating effect of interleukin-2 in the isolated aortic ring].
abstract: To explore the effect and mechanism of iron on the vasodilating effect of interleukin-2 (IL-2) in the isolated aortic ring.
  
  
  
  Isometric tension was recorded in response to drugs in organ bath. Ferric ammonium citrate (FAC) was added to the bath 30 min before phenylephrine (1 micromol/L), which was followed by IL-2 in a cumulative fashion. Spectrophotometry was used to determine the activity of nitric oxide synthase (NOS) of the thoracic aorta.
  
  
  
  FAC (0.1 - 10 micromol/L) alone did not affect the tension of rings,but inhibited the vasodilating effect of IL-2 (1 - 1,000 U/ml) in a dose dependent manner. IL-2(1, 10, 100, 1000 U/ml) decreased the aortic tension to (78.47+/-4.31)%, (66.86+/-5.55)%, (52.62+/-4.51)% and (42.39+/-4.27)% of pre-drug control, respectively. However, after incubation with 10 micromol/L FAC in the presence of IL-2, the aortic tension was reduced to (89.81+/-1.94)%, (86.13+/-3.11)%, (77.16+/-5.66)% and (68.76+/-5.69)% of pre-drug control, respectively. Pretreatment with L-arginine (1 mmol/L) abolished the inhibitory effect of FAC. Pretreatment with FAC attenuated the increased activity of NOS induced by IL-2 from (22.10+/-1.87)U/mg prot to (15.71+/-0.89)U/mg prot. High Ca(2+) (2.5 mmol/L) incubation did not change the inhibitory effect of FAC. Pretreatment with FAC attenuated the increased caffeine-releasable pool of Ca(2+) by IL-2. High K(+) (10 mmol/L) incubation abolished the inhibitory effect of FAC.
  
  
  
  FAC inhibits the vasodilating effect of IL-2 in the isolated aortic ring,which may be mediated by decreasing the activity of NOS. Intracellular calcium release and inward rectifier potassium channel are involved in the inhibitory effect of FAC.
authors.affiliation: Department of Physiology, College of Medical Sciences, Zhejiang University, Hangzhou 310031, China.
authors.forename: Lin-lin
authors.initials: LL
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xia
authors.forename: Hong-feng
authors.initials: HF
authors.lastname: Jin
authors.forename: Ying-ying
authors.initials: YY
authors.lastname: Chen
authors.forename: Qi-xian
authors.initials: QX
authors.lastname: Shan
authors.forename: Ting
authors.initials: T
authors.lastname: Shen
authors.forename: Yong
authors.initials: Y
authors.lastname: Sun
authors.forename: Yue-liang
authors.initials: YL
authors.lastname: Shen
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000502:physiology; D001120:Arginine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D005290:Ferric Compounds / Q000494:pharmacology*; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000494:pharmacology*; D008297:Male; D019001:Nitric Oxide Synthase / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D005290:Ferric Compounds; D007376:Interleukin-2; D000644:Quaternary Ammonium Compounds; D014665:Vasodilator Agents; D001120:Arginine; D019001:Nitric Oxide Synthase; D011188:Potassium; D002118:Calcium; C013531:ferric ammonium citrate