[Interleukin-2 induced endothelium-dependent relaxation of rat thoracic aorta].
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.
Cao
Chun-Mei
CM
Department of Physiology, Zhejiang University School of Medicine, Hangzhou 310031.
Ye
Song
S
Yu
Hu
H
Xu
Qing-Sheng
QS
Ye
Zhi-Guo
ZG
Shen
Yue-Liang
YL
Lu
Yuan
Y
Xia
Qiang
Q
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
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