[Treatment of interferon-alpha in reducing the endothelium-dependent relaxation of rat thoracic aorta].
To investigate the vascular effect of acute and chronic treatment of interferon-alpha (IFN-alpha) in rat aortic rings.



Isolated thoracic aortic rings were mounted on the organ bath and the tension of the vessel was recorded.



IFN-alpha(10, 100, 1,000 and 10,000 U/ml) caused concentration -dependent relaxation of endothelium-intact aorta rings preconstricted with phenylephrine (PE,10(-6)mol/L), to(90.1+/-0.91)%, (65.1+/-5.21)%, (39.5+/-8.22)% and (35.3+/-8.27)% of pre-drug control, respectively. Removal of the endothelium inhibited the relaxation by IFN-alpha. The vasorelaxant effect of IFN-alpha (100 U/ml ) was attenuated by pretreatment with L-NAME (10(-4)mol/L), methylene blue (10(-5)mol/L) or AMG (10(-4)mol/L), to (97.2+/-5.34)%, (95.1+/-6.25)% and (93.7+/-8.82)% of the control, respectively. Pretreatment with IFN-alpha (1,000,000 U/d, i.p.) for five days markedly inhibited the endothelium-dependent relaxation of the aortic rings to acetylcholine. But the endothelium-dependent relaxation to acetylcholine was not changed by pretreatment of IFN-alpha (10,000 U/ml) with the isolated aorta rings for 2 h.



The vasorelaxation induced by IFN-alpha in rat aorta rings is endothelium-dependent and is possibly mediated by inducible nitric oxide synthase. Chronic treatment of IFN-alpha may impair the endothelium or NO-sGC pathway.
Yao
Hui
H
Department of Physiology, College of Medical Sciences, Zhejiang University, Hangzhou 310031, China.
Cao
Chun-mei
CM
Jin
Hong-feng
HF
Shan
Qi-xian
QX
Wang
Lin-lin
LL
Xia
Qiang
Q
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000502:physiology; D004730:Endothelium, Vascular / Q000502:physiology*; D006162:Guanylate Cyclase / Q000502:physiology; D016898:Interferon-alpha / Q000494:pharmacology*; D008297:Male; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000502:physiology; D052247:Nitric Oxide Synthase Type II; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014664:Vasodilation / Q000187:drug effects*
D016898:Interferon-alpha; D010656:Phenylephrine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D006162:Guanylate Cyclase; D000109:Acetylcholine