尾加压素Ⅱ对大鼠血管外膜阳离子氨基酸转运体的影响

摘要

Objective To assess the gene expression of cationic amino acid transporter - 1 ( CAT - 1 ), CAT2B and inducible nitric oxide synthase (iNOS) in urotensin Ⅱ (UⅡ) - stimulated rat vascular adventitia.Methods The aortic adventitia were incubated in vitro.24 rats were randomly divided into normal group ,2U Ⅱ groups and LPS group.The aortic adventitia NO production was determined.Semi -quantitative RT- PCR was used to determine the mRNA concentrations of iNOS and CAT - 1 and CAT - 2B in aortic adventitia.Resuits After incubation of aorta for 6 hours, nitrite production in U Ⅱ group significantly increased (27％ ,P ＜ 0.05,49％, P ＜0.01 ).UⅡ - induced CAT - 1 、CAT -2B and iNOS mRNA increased significantly in aortic adventitia.Conclusion The results illustrate that U Ⅱ induces the transcription of high - affinity CAT - 1 and CAT-2B in aortic adventitia.Transcription of CAT- 1 and CAT-2B are correlated well with aortic NO biosynthesis.%目的:观察尾加压素Ⅱ(UⅡ)对大鼠主动脉血管外膜阳离子氨基酸转运体(CAT-1、CAT-2B)和诱导型一氧化氮合酶(iNOS)基因表达影响.方法:SD大鼠24只,250-3009,随机分为空白对照组、UⅡ组(10(-9)和10(-8)mol·L(-1))和脂多糖(LPS)阳性对照组,每组6只.分离雄性SD大鼠胸主动脉外膜,分别加入单纯孵育液、不同浓度UⅡ和LPS孵育6h.测定孵育液中亚硝酸盐(NO2)含量;RT-PCR方法测定CAT-1、CAT-2B和iNOS mRNA基因表达.结果:与对照组比较UⅡ(10(-9)-10(-8)·L(-1))刺激血管外膜NO2;生成增加(27%,P＜0.05,和49%,P＜0.01);UⅡ组血管外膜阳离子氨基酸转运体(CAT-1和CAT-2B)mRNA水平增加(均P＜0.01),iNOS mRNA表达增加(P＜0.01).结论:UⅡ可激活血管外膜CAT-1和CAT-2B基因表达,其变化可能参与了NO释放从而引起血管的扩张.