大鼠主动脉环张力的作用及机制
- 格式:pdf
- 大小:443.45 KB
- 文档页数:13
天麻素对大鼠离体胸主动脉血管环的作用及机制研究钟节雄;杨宏华【摘要】Objective To observe the effect and mechanism of gastrodin on isolated thoracic aorta rings in rats. Methods A perfusion model of isolated thoracic aorta ring in rats was applied to observe the direct effect of cumulative gastrodin on isolated thoracic aorta rings in rats. The same method was also used to explore the effects of the different concentration gastrodin (5μmol/L, 50μmol/L, 100μmol/L, 150μmol/L, 200μmol/L,250μmol/L) on endothelium-in-tact/denuded aorta rings pre-contracted with 10-6 mol/L phenylephrine (PE). PE was used to contract the aorta rings incu-bated by 200 mmol/L gastrodin in the Ca2+ free K-H solution, and the effect of 200 mmol/L gastrodin on aorta rings pre-contracted with 60 mmol/L KCl was observed. Results With the direct effect of gastrodin on the endothelium-in-tact vascular ring, there was no significant difference between the gastrodin group and the control group (P>0.05) on the vascular tension. With the effect of cumulative concentration of gastrodin (≥50μmol/L) on PE pre-contracted vascular ring were studied, the vascular ring relaxation rate in endothelium-intact gastrodin group and endothelium-denuded gas-trodin group were significantly higher than control group [(41.9 ± 8.9)%, (57.6 ± 9.1)%, (65.0 ± 10.2)%, (75.6 ± 11.7)%, (81.9±12.0)%vs (10.5±1.6)%, (19.4±5.9)%, (22.6±7.2)%, (24.9±6.8)%, (25.1±7.3)%, P<0.05]; Moreover, the rate of relaxation of vascular rings in the endothelium-intact gastrodin group were higher than in theendothelium-denuded gastrodin group [(20.6 ± 2.9)%, (36.5 ± 8.2)%, (43.7 ± 9.3)%, (55.7 ± 9.6)%, (58.7 ± 9.6)%) vs (9.8 ± 2.1)%, (15.8 ± 4.7)%, (18.6 ± 6.5)%, (20.3 ± 5.0)%, (21.5 ± 5.1)%, P<0.05]. F values of multi-group were respectively 5.67, 5.99, 6.11, 6.47, 7.05 (P<0.05). When the experiment was performed on the effect gastrodin on PE pre-contracted vascular ring in the calcium free fluid K-H solution, the relaxation rate in gastrodin group [(5.1 ± 1.2)%] was lower in the control group [(12.8 ± 3.7)%] (P<0.05); When the effect of gastrodin on 60 mmol/L KCl pre-contracted thoracic aortic rings, there was no significant difference between the gastrodin group [(96.7 ± 8.6)%] and the control group [(98.6 ± 7.9)%] in the vascular tension (P>0.05). Conclusion Gastrodin has no effect on intact aorta ring. The relaxation mechanism of Gas-trodin on aorta rings pre-contracted with PE is through the inhibition of release of Ca2+from the endoplasmic reticulum. Gastrodin can not inhibit the receptor-operated Ca2+channel and the voltage-dependent Ca2+channel. Therefore, the relax-ation effect of gastrodin is endothelium-dependent and concentration-dependent.%目的:观察天麻素对大鼠离体胸主动脉环的作用,并探讨其作用机制。
腺苷受体激动剂对大鼠离体主动脉的作用及其机制3曹 红 李 军 王 钧 段世明 汪 海1(徐州医学院・江苏省麻醉学重点实验室,徐州 221002)中国图书分类号 R 2332;R 3221121;R 322174;R 34214;R34215;R 34814;R 977文献标识码 A 文章编号 100121978(2000)0420413203摘要 目的 研究不同腺苷受体(A 2R )激动剂对大鼠离体主动脉环的作用及其机制。
方法 分别给予A 22R 激动剂CPCA 和A 12R 激动剂CPA ,观察离体主动脉环对0162μmol・L -1去甲肾上腺素的反应,并观察它们的作用是否依赖于血管内皮、细胞外钙和A TP 敏感性钾通道(K ATP )。
结果 50μmol ・L -1CPCA 可引起血管扩张,去除血管内皮或换用无钙营养液后此作用消失,K ATP 阻滞剂格列苯脲并不能阻断CPCA 的血管扩张作用。
CPA 在10μmol ・L -1浓度时不引起血管扩张,100μmol ・L -1浓度时有血管扩张作用,此作用在去除内皮后或换用无钙营养液后仍然存在,格列苯脲不能阻断此作用。
结论 CPCA 引起主动脉的扩张依赖于血管内皮和细胞外钙的存在,高浓度CPA 则通过直接作用于平滑肌细胞而引起血管扩张,K ATP 均不参与A 2R 激动剂的扩血管作用。
关键词 A 22受体激动剂;A 12受体激动剂;K ATP ;内皮;细胞外钙;动脉 血管是由内皮细胞、平滑肌细胞和成纤维细胞组成。
近年来发现,多种不同的肽类物质如血管紧张素Ⅱ、血管活性肠肽等也参与血管张力的调节。
内源性血管活性物质腺苷可引起血管扩张[1],但腺苷通过何种受体起作用,其作用机制尚不清楚。
本研究旨在观察腺苷受体(A 2R )A 12R 激动剂5π2(N 2cyclopropyl )2carboxamidoadenosine (CPA )和A 22R 受体激动剂N 62cyclopentyladenosine (CPCA )对离体血管的作用,探讨其与A TP 敏感性钾通道(K A TP )的关系及可能的作用机制。
海州香薷总黄酮对离体大鼠主动脉环张力的作用及机制 徐佳1 陈军津1 周育成1 王会平2 (1浙江大学医学院2004级临床医学专业3系3A班,浙江 杭州 310058; 2浙江大学医学院 生理教研室,浙江 杭州310058)
[摘要] 目的:研究海州香薷总黄酮(total flavones from Elsholtzia splendens ,TFES)对离体大鼠胸主动脉环收缩张力的作用及其机制。方法:采用大鼠离体胸主动脉灌流模型,累积加药,检测海州香薷总黄酮对去氧肾上腺素(PE)和KCL预收缩的胸主动脉环收缩张力的影响。结果:海州香薷总黄酮对内皮完整的离体主动脉环基础张力的作用不明显(p>0.05);内皮完整和去内皮时,海洲香薷总黄酮(5、10、25、50、100、200ug/mL)对PE(10-4mol/L)和KCL(3mol/L)
预收缩的血管环均产生舒张作用(p﹤0.05);而用NO 合酶(NOS)抑制剂L-NAME(10-4mol/L),鸟苷酸环化酶(GC)抑制剂ODQ(10µmol/L)以及环氧酶(COX)抑制剂Indo(10-5mol/L)处理血管后,对低浓度及高浓度下海州香薷总黄酮舒张血管效应的阻断作用均不明显(p>0.05);使用电压依赖性的K+ 通道阻断剂4-AP(1mmol/L),Ca2+ 敏感性的K+ 通道阻断剂TEA(1mmol/L)
以及ATP 敏感性的K+ 通道阻断剂格列苯脲(Glib)(3µmol/L)处理后,对海州香薷总黄酮舒血管效应的阻断作用亦均不明显;内皮完整和去内皮时,海州香薷总黄酮对PE(10-4mol/L)预收缩血管环的舒张作用均具有时间依赖性。结论:在低浓度及高浓度下,海州香薷总黄酮对大鼠离体胸主动脉环产生的舒张效应并非通过NO-鸟苷酸环化酶途径,环氧合酶途径以及直接作用于平滑肌细胞膜上电压依赖性的K+ 通道、Ca2+ 敏感性的K+ 通道、ATP 敏感性的K+ 通道的途
径产生的,其中浓度下的舒张作用可能与鸟苷酸环化酶有关,其机制待进一步研究明确。 [关键词] 海州香薷总黄酮;胸主动脉环;血管舒张;内皮
Effects and Mechanism of Total Flavonoids of Elsholtzia Splendens on Rat Thoracic aortic XU jia1,CHEN jun-jin1,ZHOU yu-cheng1,WANG hui-ping2
(1Clinical Medicine, 2Department of Physioligy,Zhejiang University School of Medicine,Hangzhou 310058,China)
[Abstract] Objective:To investigate the effect of total flavones from Elsholtzia splendens(TFES)on rat thoracic aorta rings and the underlying mechanisms. Methods: The study was performed with the model of isolate rat thoracic aorta rings in organ bath, we investigate the effects of accumulated total flavones from Elsholtzia splendens on the constriction of high KCL and Phenylephrine(PE) preconstricted rat thoracicaorta with endothelium. Results: There is no effect of total flavones from Elsholtzia splendens (TFES) on the basal tonus in rat isolated aortic rings with endothelium(p>0.05).Total flavones from Elsholtzia splendens(5、10、25、50、100、200ug/mL)concentration dependently caused relaxation in vessels with or without endothelium precontracted both with 10-4mol/L phenylephrine (PE) and 60mmol/L KCL(p<0.05).However, the relaxation evoked
by TFES of High and low concentration wasn’t inhibited by 10-4mol/L NG-nitro-L-arginine methyl
ester (L-NAME),10µmol/L guanyly cyclase inhibitor 1H-[1,2,4] oxadiazolo [4,3-alpha] quinoxalin-1-one (ODQ) and 10-5mol/L Indomethacin(Indo)(p>0.05). Also, the relaxation to the total
flavones from Elsholtzia splendens was not inhibited by 1mmol/L tetraethylammonium (TEA) 、1mmol/L 4-aminopyridine(4-AP)and 3µmol/L Glibenclamide(Glib). TFES time dependently caused relaxation in vessels with or without endothelium precontracted with 10-4mol/L phenylephrine
(PE).Conclusion:The results indicate that TFES can relax the rat thoracic aorta rings with or without endothelium . At the same time, the relaxation by TFES of High and low concentration isn’t mediated by the NO-guanylyl cyclase pathway ,COX pathway and three kinds of K+-channels on the membrane
of vascular smooth muscle,yet,the relaxation by TFES of mediate concentration may be mediated by GC,so the mechanisms need more research. [Key words] TFES; thoracic aorta rings;vascular relaxation;endothelium 香薷(Elsholtzia Splendens)是传统中药,主要用于治疗暑湿感冒、恶寒发热、头痛无汗,也用于治疗腹痛吐泻,小便不利,风湿关节痛等疾病[1]。近来研究表明它还有抗氧化活性、心肌缺血保护、加强内分泌系统免疫、降血脂、抗炎症、抗病原微生物等作用。香薷化学成分复杂,包括黄酮类、香豆素类、木脂素类、萜类,以及各种脂肪酸、挥发油等[2]。早在20世纪60
年代,国内外就已研究并证实了银杏叶总黄酮(FG)的扩血管活性,并已初步用于临床,获得较好的疗效[2]。另外据相关研究表明,生物类黄酮具有抗氧化、降低脂质过氧化反应、预防心血
管疾病、抗氧、防癌等作用[3]。而香薷总黄酮对血管的作用及其机制方面的研究基本尚属空白。因此,本实验采用大鼠离体胸主动脉灌流模型,在内皮完整和去内皮的条件下,累积加药,检测海州香薷总黄酮对去氧肾上腺素(PE)和KCL预收缩的胸主动脉环收缩张力的影响,探讨其对血管平滑肌的作用及可能的机制。
1 材料与方法 1.1 设备 离体血管环灌流装置,JZJ01 型肌肉张力换能器,HSS-1B 型数字式超级恒温浴槽,RM6240B 型多道生理信号采集处理系统,均为成都仪器厂产品。 1.2 药物与试剂 苯肾上腺素(Phenylephrine,PE),乙酰胆碱(Acetylcholine,Ach),左旋硝基精氨酸甲脂(N(omega)-nitro-L-methyl-ester ,L-NAME), 吲哚美辛( Indomethacin , Indo ),1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one(ODQ),格列苯脲(Glibenclamide),以上均为Sigma公司产品,海州香薷总黄酮由王会平老师提供,用K-H 液配制含海洲香薷总黄酮原液。Krebs-Henseleit (K-H)液(mmol/L):NaCL 118、KCL 4.7、KH2PO4 1.2、MgSO4 •7H2O 1.2、NaHCO325,glucose 10、CaCL2 1.25。 1.3 血管环的制备 Sprague-Dawley(SD)大鼠,雄性,体重200-280 g,由浙江大学医学院动物实验中心提供。每个大鼠的胸主动脉被分成6-8 段,并随机分入8 个实验组进行平行研究。具体方法为:用钝器击昏大鼠后充分放血,迅速取胸主动脉,置于通以95%O2和5%CO2混合气体预饱和地4°C K-H液中,去除周围结缔组织后将血管剪成约3~4mm的血管环,避免过度牵拉,以防损伤内皮。根据实验需要,去除血管内皮时,用镊子磨擦血管环内表面以去除内皮细胞。将血管环悬挂于预置10ml K-H液的浴槽内,37°C恒温,持续通以95%O2和5%CO2的混合气体。静息张力1g稳定血管30min,每隔15min换一次K-H液,每隔10min调整一下张力使其稳定在1g,此后调节静息张力为2g,稳定稳定1h,期间每隔15min换一次K-H液每隔10min调整一下张力使其稳定在2g。用3mol/L的KCL重复刺激3次,以诱发血管的最大收缩幅度。待血管稳定后,用10-4
mol/L PE预收缩血管环达峰值,加入10-4 mol/L Ach检验内皮的完整性。加入Ach后使PE预收缩的血管环舒张60%~90%,认为内皮完整,反之,认为内皮被破坏。实验用RM6240B 型生物信号采集处理系统记录血管张力的变化,分别以末次KCL(终浓度6×10-2mol/L)、PE(终浓度10-6 mol/L)刺激引起的最大收缩幅度为标准,以加入药物后的血管张力幅度与之相比所得百分比比值表示。 1.4 实验分组 1.4.1ES对主动脉环基础张力影响组。ES对内皮完整主动脉环基础张力影响组(n=3):采用累积加药方法,每18 min加入ES,使灌流液中ES浓度分别达5、10、25、50、100、200 μg/ml;ES对去内皮主动脉环基础张力影响组(n=4):使用去除内皮血管环,其余方法同上。 1.4.2ES对PE预收缩主动脉环张力影响组。ES对内皮完整PE预收缩主动脉环张力影响组(n=13):PE(1μmol/L)预收缩达稳态后,采用累积加药方法,每18 min加入ES,使灌流液中ES浓度分别达5、10、25、50、100、200 μg/ml;ES对去内皮PE预收缩主动脉环张力影响组(n=6):使用去除内皮血管环,其余方法同上。 1.4.3ES对KCl预收缩主动脉环张力影响组。ES对内皮完整KCl预收缩主动脉环张力影响组(n=9):KCl (6×10-2mol/L)预收缩达稳态后,采用累积加药方法,每18 min加入ES,使灌流液中ES浓度