摘要
目的研究乙酰异羟肟酸(AHA)降血压和舒张胸主动脉血管的作用及其机制。方法(1)动物实验:8周龄SD雄性大鼠,ip给予AHA 50和100 mg·kg^-1,每5 d给药1次,共5次。分别在给药前1 d、给药第13天和给药第26天测收缩压(SBP)和舒张压(DBP);HE染色观察大鼠胸主动脉血管组织形态变化。(2)离体实验:①累积浓度AHA(0.1,1,3,10,30和100μmol·L^-1)处理大鼠离体胸主动脉内皮完整血管环,检测血管环张力。②大鼠离体胸主动脉内皮完整和去内皮血管环用去甲肾上腺素(NE,1μmol·L^-1)和KCl(60 mmol·L^-1)预收缩,稳定后每10 min累积加入AHA(0.1,1,3,10,30和100μmol·L^-1),计算血管舒张百分比。③内皮完整血管环分为AHA组、AHA+左旋硝基精氨酸甲酯(L-NAME)组和AHA+吲哚美辛(Indo)组。L-NAME(0.1 mmol·L^-1)或Indo(0.01 mmol·L^-1)孵育30 min后,加NE(1μmol·L^-1)预收缩,血管收缩稳定后,累积加入AHA(0.1,1,3,10,30和100μmol·L^-1),计算累积浓度AHA舒张血管百分比。④内皮完整血管环分为AHA组、AHA+4-氨基吡啶(4-AP,1 mmol·L^-1)、AHA+格列苯脲(Gli,0.01 mmol·L^-1)、AHA+澳化四乙胺(TEA,1 mmol·L^-1)和AHA+BaCl2(0.1 mmol·L^-1)组。4-AP,Gli,TEA和BaCl2孵育30 min后,加NE(1μmol·L^-1)预收缩,血管收缩稳定后,累积加入AHA(0.1,1,3,10,30和100μmol·L^-1),计算累积浓度AHA血管舒张百分比。⑤内皮完整血管环分为AHA 1,10和100μmol·L^-1组,实验组分别加入不同浓度的AHA,预孵30 min后,加入累积浓度的CaCl2(0.1,0.3,1,3和10 mmol·L^-1),计算AHA各实验组血管收缩百分比。⑥内皮完整血管环分为AHA 1,10和100μmol·L^-1组,实验组分别加入不同浓度的AHA,预孵30 min后加入NE(1μmol·L^-1),计算AHA各实验组血管收缩张力。结果(1)动物实验:与正常对照组相比,AHA 50和100 mg·kg^-1组大鼠SBP和DBP均显著降低(P<0.01);HE染色未见AHA组大鼠胸主动脉组织形态明显改变。(2)离体实验:①累积浓度AHA对静息状态的大鼠胸主动脉内皮完整血管环张力无明显影响;②累积浓度AHA对KCl预收缩的胸主动脉环张力无明显影响,而AHA可浓度依赖性地舒张NE预收缩胸主动脉环,且去内皮组舒张程度弱于内皮完整组(P<0.01);③L-NAME和Indo均可明显抑制AHA的舒血管作用(P<0.01);④钾离子通道阻滞剂TEA和BaCl2均可明显抑制AHA的舒血管作用(P<0.01),4-AP和Gli无明显影响;⑤AHA能降低NE预收缩下细胞外钙内流引起大鼠离体胸主动脉内皮完整血管环的收缩张力(P<0.01),并使氯化钙收缩作用曲线右移;⑥AHA能降低经NE预收缩、由细胞内钙释放引起的大鼠离体胸主动脉内皮完整血管环的收缩张力(P<0.01)。结论AHA具有降低正常大鼠血压和舒张胸主动脉血管环的作用,其机制可能与血管内皮、钙敏感性钾通道、内向整流型钾通道及细胞内钙释放和外钙内流有关。
OBJECTIVE To investigate the effect of acetohydroxamic acid(AHA)on lowering blood pressure and relaxing the thoracic aorta.METHODS(1)Animal experiment:8-week-old SD male rats were randomly divided into normal control group(ip equal volume of saline),AHA 50 and 100 mg•kg-1.The drug was administered once every 5 d for a total of 5 times,and the systolic and diastolic blood pressure of the rats were measured with a non-invasive sphygmomanometer on the day before,the 13th and the 26th day of administration.The morphological changes of the thoracic aorta and blood vessels were observed by HE staining.(2)In vitro experiment:①The cumulative concentration of AHA(0.1,1,3,10,30 and 100μmol·L^-1)was used to treat the complete vascular ring of the isolated thoracic aorta endothelium in rats to detect the ring tension.②When the rat thoracic aortic ring with End+and End-was pre-contracted with norepinephrine(NE)1μmol·L^-1 and KCl 60 mmol·L^-1 for 10 minutes,AHA(0.1,1,3,10,30 and 100μmol·L^-1)and saline were cumulatively added into the organ bath.③The endothelium-intact(End+)vascular ring of the thoracic aorta was divided into the AHA group,AHA+L-NAME group and AHA+Indo group.After NG-nitro-L-arginine methyl ester(L-NAME)0.1 mmol·L^-1 or indomethacin(Indo)0.01 mmol·L^-1 was incubated for 30 min,NE(1μmol·L^-1)was added for pre-constriction.After the vasoconstriction was stabilized,AHA(0.1,1,3,10,30 and 100μmol·L^-1)was cumulatively added into the organ bath before the cumulative concentration of AHA was calculated as a percentage of diastolic blood vessels.④The endothelium-intact(End+)vascular ring of the thoracic aorta was divided into AHA group,AHA+4-AP group,AHA+Gli group,AHA+TEA group and AHA+BaCl2 group.After 4-aminopyridine(4-AP)1 mmol·L^-1,glibenclamide(Gli)0.01 mmol·L^-1,tetraethylammonium(TEA)1 mmol·L^-1 and barium chloride(BaCl2)1 mmol·L^-1 were incubated for 30 min,NE(1μmol·L^-1)was added to induce pre-constriction.After the vasoconstriction was stabilized,AHA(0.1,1,3,10,30 and 100μmol·L^-1)was cumulatively added into the organ bath,the cumulative concentration of AHA was calculated as a percentage of diastolic blood vessels.⑤The endothelium-intact(End+)vascular ring of the thoracic aorta was divided into AHA 1μmol·L^-1 group,AHA 10μmol·L^-1 group and AHA 100μmol·L^-1 group,different concentrations of AHA(1,10,and 100μmol·L^-1)were added to the experimental group,while cumulative concentrations of CaCl2(0.1,0.3,1,3 and 10 mmol·L^-1)were added after pre-incubation of 30 min.The percentage of vasoconstriction in each AHA group was calculated.⑥The endothelium-intact(End+)vascular ring of the thoracic aorta was divided into AHA 1,10 and 100μmol·L^-1 group.After the experimental groups were added with different concentrations of AHA(1,10 and 100μmol·L^-1)for 30 min,NE(1μmol·L^-1)was added into the organ bath,and the vasoconstriction tension of each AHA group was calculated.RESULTS(1)Animal experiment:the systolic and diastolic blood pressure of the AHA group decreased compared with the normal control group(P<0.01).HE staining did not find any obvious changes in the morphology of the thoracic aorta in any group.(2)Isolated vascular ring experiment:①The cumulative concentration of AHA had no significant effect on resting-state thoracic aortic ring tension.②The cumulative concentration of AHA had no significant effect on the tension of the thoracic aortic ring pre-contracted with KCl,while AHA could relax the NE pre-contracted thoracic aortic ring in a concentration-dependent manner(P<0.01),and it had a stronger vasodilating effect on the endothelium-intact thoracic aorta than on the endothelium-denuded thoracic aorta.③After treatment with L-NAME and Indo,the vasodilation effect of AHA was obviously decreased(P<0.01).④After treatment with TEA and BaCl2,the vasodilation effect of AHA was obviously decreased(P<0.01),but the application of 4-AP and Gli had no effect on the vasodilation effect of AHA.⑤AHA could reduce the contractile tension of the intact vascular ring of the isolated thoracic aorta endothelium caused by extracellular calcium influx under NE precontraction(P<0.01),and shift the dose-response curve of calcium chloride contraction to the right.⑥AHA could reduce the intracellular calcium release under NE pre-contraction and induce the contractile tension of the intact vascular ring of the isolated thoracic aorta endothelium in rats(P<0.01).CONCLUSION These results indicate that AHA lowers blood pressure in normal rats,and that AHA has a relaxing effect on the thoracic aorta.The diastolic mechanisms may be related to vascular endothelium,KCa,KIR,and intracellular calcium release and extra calcium influx.
作者
李发珍
谢童
范彦英
杨彩红
LI Fa-zhen;XIE Tong;FAN Yan-ying;YANG Cai-hong(Department of Pharmacology,Shanxi Medical University,Taiyuan 030001,China)
出处
《中国药理学与毒理学杂志》
CAS
北大核心
2020年第6期418-427,共10页
Chinese Journal of Pharmacology and Toxicology
基金
山西省自然科学基金(201901D111198)
山西省“1331工程”重点学科建设计划基金(XK201708)。
关键词
乙酰异羟肟酸
胸主动脉
血管内皮
钙通道
acetohydroxamic acid
thoracic aorta
vascular endothelium
calcium channels
作者简介
李发珍,硕士研究生,主要从事心血管药理学与毒理学研究;通讯作者:杨彩红,E-mail:tyyangxiaoluo@163.com。
