一氧化氮供体GEA 3175对牛离体细支气管的舒张机制。

Mechanisms of relaxations of bovine isolated bronchioles by the nitric oxide donor, GEA 3175.

作者信息

Hernández M, Elmedal B, Mulvany M J, Simonsen U

机构信息

Department of Pharmacology, University of Aarhus, Denmark.

出版信息

Br J Pharmacol. 1998 Mar;123(5):895-905. doi: 10.1038/sj.bjp.0701684.

DOI:10.1038/sj.bjp.0701684

PMID:9535018

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1565239/

Abstract

The present study was designed to investigate the effects and mechanisms of relaxation induced by the nitric oxide (NO) donor, GEA 3175 (a 3-aryl-substituted oxatriazole derivative) on bovine bronchioles (effective lumen diameter 200-800 microm) suspended in microvascular myographs for isometric tension recording. 2. In segments of bovine bronchioles contracted to 5-hydroxytryptamine, GEA 3175 (10(-8)-10(-4) M) induced concentration-dependent reproducible relaxations. These relaxations were slow in onset compared to other NO-donors such as 3-morpholinosydonimine-hydrochloride (SIN-1) and S-nitroso-N-acetylpenicillamine (SNAP). 3. In 5-hydroxytryptamine-contracted preparations the order of relaxant potency (pD2) was: salbutamol (7.80) > GEA 3175 (6.18) > SIN-1 (4.90) > SNAP (3.55). In segments contracted to acetylcholine, the relaxant responses were reduced and GEA 3175 relaxed the bronchioles with pD2 = 4.41 +/- 0.12 and relaxations of 66 +/- 10% (n = 4), while SNAP and salbutamol caused relaxations of 19 +/- 6% (n = 4) and 27 +/- 6% (n = 8) at the highest concentration used, respectively. 4. Oxyhaemoglobin (10(-5) M), the scavenger of nitric oxide, caused rightward shifts of the concentration-relaxation curves to GEA 3175 and NO. 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ, 3 x 10(-6) M) and LY 83583 (10(-6) M), the inhibitors of soluble guanylate cyclase, also reduced the relaxations induced by GEA 3175 and nitric oxide. However, ODQ did not affect salbutamol-evoked relaxation in the bovine small bronchioles. 5. GEA 3175-induced relaxations were reduced in potassium-rich (60 mmol l(-1) K+) solution. Glibenclamide (10(-6) M) markedly inhibited the relaxations induced by the opener of ATP-sensitive K+ channels, levcromakalim (3 x 10(-8)-10(-5) M), but it did not modify the relaxations induced by GEA 3175 or salbutamol. Apamin (5 x 10(-7) M), a blocker of the small Ca2+-activated K+-channels did not affect the relaxations to GEA 3175. In contrast, blockers of large Ca2+-activated K+-channels, charybdotoxin (3 x 10(-8)-10(-7) M) and iberiotoxin (10(-8) M), did inhibit the relaxations to GEA 3175. The combination of apamin and charybdotoxin did not induce an additional inhibitory effect on the relaxations to GEA 3175 compared to charybdotoxin alone. 6. In preparations where a concentration-response curve to GEA 3175 or NO was first obtained in the presence of LY 83583, incubation with charybdotoxin (10(-7) M) did produce an additional inhibitory effect of the relaxations. However. in the presence of ODQ (3 x 10(-6) M), iberiotoxin (10(-8) M) did not produce additional reduction of the NO- or GEA 3175-induced relaxations. 7. The present results suggest that the slow-releasing NO-donor GEA 3175 is more potent than the traditional NO donors in inducing relaxations of bovine bronchioles. GEA 3175, as for exogenously added NO, elicits relaxations through a cyclic GMP-dependent mechanism followed by opening of large conductance Ca2+-activated K+-channels.

摘要

本研究旨在探讨一氧化氮（NO）供体GEA 3175（一种3-芳基取代的氧杂三唑衍生物）对悬浮于微血管肌动描记器中用于等长张力记录的牛细支气管（有效管腔直径200 - 800微米）产生舒张作用的效果及机制。2. 在被5-羟色胺收缩的牛细支气管节段中，GEA 3175（10⁻⁸ - 10⁻⁴ M）诱导出浓度依赖性的可重复性舒张。与其他NO供体如盐酸3-吗啉代 sydonimine（SIN-1）和S-亚硝基-N-乙酰青霉胺（SNAP）相比，这些舒张起效缓慢。3. 在被5-羟色胺收缩的制剂中，舒张效力（pD2）顺序为：沙丁胺醇（7.80）> GEA 3175（6.18）> SIN-1（4.90）> SNAP（3.55）。在被乙酰胆碱收缩的节段中，舒张反应减弱，GEA 3175使细支气管舒张，pD2 = 4.41 ± 0.12，舒张率为66 ± 10%（n = 4），而在所用最高浓度时，SNAP和沙丁胺醇分别引起19 ± 6%（n = 4）和27 ± 6%（n = 8）的舒张。4. 一氧化氮清除剂氧合血红蛋白（10⁻⁵ M）使GEA 3175和NO的浓度 - 舒张曲线右移。可溶性鸟苷酸环化酶抑制剂1H-[1,2,4]恶二唑并[4,3,-a]喹喔啉 - 1 -酮（ODQ，3 × 10⁻⁶ M）和LY 83583（10⁻⁶ M）也降低了GEA 3175和一氧化氮诱导的舒张。然而，ODQ不影响牛小细支气管中沙丁胺醇引起的舒张。5. 在富含钾（60 mmol l⁻¹ K⁺）的溶液中，GEA 3175诱导的舒张减弱。格列本脲（10⁻⁶ M）显著抑制ATP敏感性钾通道开放剂左卡尼汀（3 × 10⁻⁸ - 10⁻⁵ M）诱导的舒张，但不改变GEA 3175或沙丁胺醇诱导的舒张。蜂毒明肽（5 × 10⁻⁷ M），一种小Ca²⁺激活钾通道阻滞剂，不影响对GEA 3175的舒张。相反，大Ca²⁺激活钾通道阻滞剂，蝎毒素（3 × 10⁻⁸ - 10⁻⁷ M）和iberiotoxin（10⁻⁸ M），确实抑制对GEA 3175的舒张。与单独使用蝎毒素相比，蜂毒明肽和蝎毒素的组合对GEA 3175诱导的舒张没有产生额外的抑制作用。6. 在预先存在LY 83583的情况下首先获得GEA 3175或NO浓度 - 反应曲线的制剂中，用蝎毒素（10⁻⁷ M）孵育确实对舒张产生了额外的抑制作用。然而，在存在ODQ（3 × 10⁻⁶ M）的情况下，iberiotoxin（10⁻⁸ M）没有使NO或GEA 3175诱导的舒张进一步降低。7. 目前的结果表明，缓慢释放的NO供体GEA 3175在诱导牛细支气管舒张方面比传统的NO供体更有效。GEA 3175与外源性添加的NO一样，通过环磷酸鸟苷依赖性机制引发舒张，随后开放大电导Ca²⁺激活钾通道。