抗高血压因子的实验研究 Ⅱ.抗高血压因子降压机理的初步研究(简报)

Ca~(2 )与高血压发病密切相关,血管平滑肌(VSM)细胞内持续高Ca~(2 )水平是导致VSM张力增加、血压升高的根本原因。为了分析抗高血压因子(AHF)降压机理是否与抑制血管平滑肌Ca~(2 )内流有关,本实验观察AHF对大鼠动脉条Ca~(2 )内流及对大鼠离体血管舒张作用的影响。 一、Ca~(2 )内流实验 实验观察不同浓度AHF(10~(-7),10~(-6)和10~(-5)g/ml)对卒中易感型SHR(SH-Rsp,n=4)及WKY大鼠(n=5)主动脉(A)及肠系膜动脉(MA)条Ca~(2 )内流的影响。以~45Ca为     

川芎嗪及丹参对正常及高血压大鼠动脉平滑肌Ca~(2+)内流的动力学影响

钙(Ca)与高血压发病密切相关.血管平滑肌(VSM)细胞内持续的高钙水平,导致VSM紧张,最终引起高血压.胞内高钙浓度的主要原因是Ca~+内流与外流机制障碍。正常时,Ca~(2+)内流与外流速率处于动态平衡,维持着细胞内低外高的钙的浓度差。本工作比较了正常及高血压大鼠主动脉(AS)及肠系膜动脉(MS)平滑肌Ca~(2+)内流情况,并观察川芎嗪及丹参对Ca~(2+)内流的影响。     

红细胞抗高血压因子对大鼠血管平滑肌细胞升高的钙浓度的影响（简报）

红细胞抗高血压因子（antihypertensivefactor，AHF）是近年本实验室从动物和人的红细胞中提取的一种具有降压作用的小分子物质。已有的研究发现，其降压机制与其呈内皮依赖性的舒张血管平滑肌（VSM），减弱心功能，降低Ca2 内流，抑制血管平滑肌细胞（VSMC）增殖及。c－myc和CaM基因表达有密切关系。本实验观察了从火红细胞中提取的抗高血压因子（AHF）对自发性高血压大鼠（SHR）和正常血压WKY大鼠培养的主动脉平滑肌细胞胞内游离Ca2 浓度（[Ca2 ]i）的影响，以进一步揭示其降压作用与VSMC［Ca2 ］i的关系，为寻找防治高血压的…     

大鼠红细胞抗高血压因子的降压作用

本实验表明,从自发性高血压大鼠(SHR)红细胞提取的抗高血压因子(antihyper-tensive factor,AHF)可明显而持久地降低SHR和肾性高血压大鼠(RHR)的血压,而对正常大鼠血压无影响,表明AHF的降压作用与动物原来的血压水平密切相关,即具有血压依赖性;AHF耐热,在沸水中处理15min仍保持其强烈的降压效果,提示其不可能是体内已知的一些舒血管物质。目前,作者正在对AHF的理化特性和降压机理进行更深入的研究。     

通心络对自发性高血压大鼠血浆NO、ET及血管平滑肌iNOS表达的影响

目的 观察通心络对自发性高血压大鼠(SHR)血压、血浆内皮素(ET)、一氧化氮(NO)、血管紧张素Ⅱ(Ang Ⅱ)以及主动脉血管平滑肌组织(VSM)iNOS mRNA表达的变化. 方法 30只12周龄雄性SHR大鼠,随机分成3组,每组10只,分别为空白对照组、通心络小剂量组、大剂量组,年龄、性别配对的正常雄性WKY大鼠作为时照.各给药组均采用灌胃法给药,对照组给予等量蒸馏水.治疗12周.放免法测定血浆ET、Ang Ⅱ浓度,NO浓度采用硝酸还原酶法测定,用RT-PCR检测VSM组织iNOS mRNA表达水平. 结果 与未治疗组SHR相比,大、小剂量通心络治疗均能在一定程度上抑制SHR大鼠血压升高(P<0.05);小剂量通心络治疗可降低血浆ET浓度(P<0.05),升高NO浓度(P<0.05),Ang Ⅱ浓度无明显变化(P>0.05),VSM iNOS mRNA表达增强(P<0.05);大剂量通心络治疗可使血浆ET明显降低(P<0.01),Ang Ⅱ浓度下调(P<0.05),NO浓度显著升高(P<0.01),VSM iNOS mRNA表达显著增强(P<0.01). 结论 通心络治疗能有效降低SHR大鼠血浆ET、Ang Ⅱ水平,促进VSM组织iNOS mRNA表达,增加血浆NO浓度,抑制血压的升高.     

心痛定对自发性高血压大鼠血压及血浆和组织中钙调素含量的影响

中国医学科学院有关人类及各种实验性高血压动物钙代谢障碍的资料表明,作为钙受体的钙调素(Calmoclulin,CaM)可能与高血压发病密切相关。在自发性高血压大鼠(SHR),自发性高血压小鼠(SHM)和肾性高血压大鼠,我们曾观察到肾脏、心脏和主动脉CaM含量明显高于对照动物。为了进一步探讨Ca~(2+)     

缺血及缺血/再灌心律失常大鼠心肌~(45)Ca~(2+)内流变化

本实验采用麻醉大鼠缺血、及缺血再灌心律失常法以及同位素示踪法,对大鼠心肌缺血40mm和缺血10mm再灌30mm心律失常发生与心肌损伤致~(45)Ca~(2+)内流的变化进行了观察。结果表明,心肌缺血40mm心律失常发生较轻VF(53％),~(45)Ca~(2+)内流不明显(与正常心肌组比P>0.05)。缺血10mm再灌30mm心律失常发生严重(91％),室颤发生率较高(80％),~(45)Ca~(2+)内流量明显增加(与正常,缺血心肌组比P<0.01)。证实缺血性心律失常与心肌损伤引起Ca~(2+)内流关系不明显,而再灌心律失常的发生则与心肌损伤引起Ca~(2+)内流增加有关。     

依脉特灵对高血压大鼠的降压作用

本文报告IT对高血压大鼠降压作用。结果对SHR有效,对CHR无效。SHR100mg/kg、150mg/kg po,1天1次,连续4wk,MAP、ASP、ADP均有不同程度降低,剂量增加作用更为明显,尤以ADP下降更显著,与对照组比较下降36.4％,对CHR无明显降压作用。SHR100mg/kg十二指肠给药,MAP下降以4h最为明显,与NF比较,其降压强度为1:1.03。SHR150mg/kgpo,1天1次4wk后,肝脏重量与对照组比较增加11.1％,SGPT升高7.1％,镜检无病理学变化,提示IT长期应用时应注意患者肝功的变化。IT降压机制可能与其拮抗Ca~(2+)有关。     

原发性高血压患者红细胞膜Ca~(2+)—ATP酶活性的初步观察

细胞膜 Ca~(2+)—ATP 酶对细胞内 Ca~(2+)转运发挥泵的作用。本文观察了20例原发性高血压患者红细胞膜 Ca~(2+)-ATP 酶活性并与正常人比较,发现该酶话性明显低于正常人,提示高血压患者依赖 ATP 的 Ca~(2+)转运能力降低。并同时观察到高血压患者尿 Ca~(2+)排出量与正常人比较明显增加。     

抗高血压因子对老年心肌梗死血栓形成的抑制作用

目的 探讨抗高血压因子（AHF）在老年心肌梗死时对血栓形成的抑制作用及机制。方法 以老龄大鼠心肌梗死模型,腹腔注射AHF加以保护。结果 AHF保护组较非保护组心肌内血栓数量降低了53．8％,心肌内钙含量降低37．1％,血浆中血栓素B2（TXB2）降低45．6％和血小板聚集率（PAg)降低了50．5％;前列环素（6－Keto-PGF1a)则增加了80．2％。AHF对凝血酶诱发的老年人血小板内Ca^2 浓度的增加值可降低19．3％（均P＜0．05）。结论 AHF在老年心肌梗死时对血栓形成具有明显抑制作用,其机制与AHF防止心肌细胞钙超载、降低血浆TXB2／6－Keto-PGF1a的比值及抑制血小板Ca^2 内流,从而抑制血小板的聚集有关。     

抗高血压因子对正常及高血压动物动脉平滑肌C...

Aorta segments (A) and mesenteric arteries (MA) from stroke prone spontaneously hypertensive rats (SHRsp) and control Wistar Kyoto rats (WKY) were used in the present study to assess the effect of AHF on Ca2+ influx in vascular smooth muscle (VSM). The results indicated that Ca2+ influx in VSM of SHRsp was much higher than that of WKY rats (P less than 0.05). AHF at 10(-7), 10(-6) and 10(-5) g/ml can significantly inhibit Ca2+ influx in a dose-dependent manner in VSM of both A and MA (P less than 0.05 and less than 0.01). The suppression effect of AHF on Ca2+ influx and the concentration-dependent relationship were more obvious in MA than in A. The Ca2+ influx in VSM of WKY rats was unaffected by administration of AHF.     

Effects of antihypertensive factor from erythrocyte of spontaneously hypertensive rats on the blood pressure and Ca2+ influx of arterial smooth muscle in rats.

The effects of a partially purified antihypertensive factor (AHF) from erythrocytes of spontaneously hypertensive rats (SHR) on the blood pressure (BP) and Ca2+ influx of vascular smooth muscle (VSM) in rats were studied. The results indicated that AHF could produce a marked prolonged depressor effect and significantly inhibit the Ca2+ influx dose-dependently on both SHR and renal hypertensive rat (RHR) either in acute or in chronic experiments, but not on normotensive rats. It suggested that the inhibition of Ca2+ influx might be one of the important mechanisms for AHF as an endogenous depressor substance.

     

抗高血压因子对自发性高血压大鼠心脏功能的影响

本实验观察正常人红细胞抗高血压因子(antihypertensive factor,AHF)对卒中易感型自发性高血压大鼠(SHRsp)在体和离体心脏功能的影响。结果表明:AHF显著降低SHRsp在体心脏的心率(HR)、左心室收缩压(LVESP)和左心室内收缩及舒张压最大变化速率(±LVdP/dtmax)。而对正常血压的WKY大鼠上述指标无明显影响,表明AHF对高血压动物在体心脏具有负性变时和变力作用。AHF能明显降低SHRsp离体心脏的收缩幅度和静息张力,而对HR和冠状动脉流量无明显影响,表明AHF对离体心脏具有负性变力效应。以上结果提示AHF的降压作用与其降低心脏功能有关。     

Atrial natriuretic factor and renin synthesized in cultured aortic smooth muscle cells of rats.

This study was designed to determine whether or not atrial natriuretic factor (ANF) is present in the vascular walls and to observe the differences in ANF between control (WKY) and stroke-prone spontaneously hypertensive rats (SHRsp). It was found that ANF is indeed present in the vascular wall of the distal aorta. HPLC analysis of the extracts from cultured aortic smooth muscle cells (ASMC) and medium revealed that intracellular ANF was mainly in the form of ANF(1-126), at levels of 0.82 +/- 0.03 (SHRsp) and 1.04 +/- 0.10 ng/10(6) cells (WKY), while the major form in the medium was ANF(99-126), at levels of 0.40 +/- 0.06 and 0.60 +/- 0.06 ng/10(6) cells, respectively. Both forms were present in smaller amounts in SHRsp than in WKY rats. On the contrary, both renin activity and angiotensin I concentrations in SHRsp cells were significantly higher than those in the WKY controls. In addition, immunocytochemistry showed positive ANF staining in cultured ASMC of both strains. The results suggest that ANF can be synthesized and secreted by cultured ASMC from rats.     

硝普钠对SHRsp阻力血管平滑肌钙激活钾通道的影响

目的 观察硝基类扩血管药硝普钠（ｓｏｄｉｎｍ ｎｉｔｒｏｐｒｕｓｓｉｄｅｍ,ＳＮＰ）对卒中易感型自发高血压大鼠（ＳＨＲｓｐ）及其正常血压对照ＷＫＹ大鼠肠系膜动脉Ａ４－Ａ５分支阻力血管平滑肌钙激活钾通道（ＫＣａ）的作用。方法 用细胞贴附式膜片箝（ｏａｔｃｈ ｃｌａｍｐ）技术。结果 发现ＳＮＰ可激活ＳＨＲｓｐ与ＷＫＹ阻力血管平滑肌ＫＣａ。在同等剂量（１ ｎｍｏｌ／Ｌ）ＳＮＰ作用下,被激活的ＳＨＲｓｐ     

氢气对单关节炎大鼠的保护作用

目的 观察经呼吸道吸入氢气对单关节炎大鼠的保护作用。方法 40只雄性SD大鼠随机分为5组：单关节炎组、单关节炎+氢气0~14 d组、单关节炎+氢气0~3 d组、单关节炎+氢气4~14 d组、假手术+氢气0~14 d组,每组8只。于大鼠左侧踝关节腔注射完全弗氏佐剂（CFA）建立单关节炎模型。单关节炎组大鼠不吸入氢气,另4组大鼠分别在造模当天及造模后第1~14天每天吸入65%氢气1.5 h、在造模当天及造模后第1~3天每天吸入65%氢气1.5 h、在造模后第4~14天每天吸入65%氢气1.5 h、在假手术当天及造模后第1~14天每天吸入65%氢气1.5 h。采用von Frey纤毛测定单关节炎大鼠双侧后爪在建模后0、1、3、5、7、10、14 d的机械刺激抬腿反应阈值（PWT）。另取15只大鼠分为5组,每组3只,于造模或假手术后第10天取致炎侧脊髓腰膨大组织,用大鼠超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、丙二醛（MDA）检测试剂盒分别检测致炎侧脊髓组织中SOD、CAT、MDA的含量。结果 单关节炎组大鼠致炎侧后爪PWT在建模后第1天即低于健侧,在第3天达到最低值并维持稳定至第14天（P<0.01）。单关节炎+氢气0~14 d组和单关节炎+氢气0~3 d组大鼠致炎侧后爪PWT均高于单关节炎组致炎侧（P<0.05,P<0.01）;单关节炎+氢气4~14 d组大鼠致炎侧后爪PWT与单关节炎组致炎侧相比差异无统计学意义（P>0.05）。单关节炎+氢气0~14 d组致炎侧脊髓组织中SOD、CAT水平均高于单关节炎组（P均<0.05）,MDA水平低于单关节炎组（P<0.05）,而单关节炎+氢气0~3 d组和单关节炎+氢气4~14 d组致炎侧脊髓组织中SOD、CAT和MDA水平与单关节炎组比较差异均无统计学意义（P均>0.05）。结论 经呼吸道吸入65%氢气在大鼠单关节炎模型的起始阶段可减轻机械痛敏及氧化应激,预先给予氢气可抑制单关节炎机械痛敏的形成。     

心钠素对高血压大鼠动脉平滑肌细胞离子泵活性和基因表达的影响

目的 探讨心钠素(ANP)对自发性高血压大鼠(SHR)动脉平滑肌细胞膜(ASMC)Na+,K+-ATP酶、Ca2+-ATP酶活性及Na+,K+-ATP酶α,亚单位、Ca+-ATP)酶亚型1(PMCA1)mRNA表达的影响.方法 对SHR大鼠,予不同浓度ANP和血管紧张素Ⅱ(Ang Ⅱ)干预,通过放射免疫、生化酶学和逆转录-聚合酶链反应等方法,检测ASMC的ANP、AngⅡ含量,ATP酶活性及其mRNA表达变化并设WKY大鼠为对照.结果 SHR大鼠ANP含量比WKY大鼠下降[(7.3±2.4)pg·10-6比(19.3±3.3) Pg·10-6,P＜0.01],Ang Ⅱ含量增加[(57±4)pg·10-6比(44±4) pg·10-6,P＜0.01],Na+,K+-ATP酶、Ca2+-A11)酶活性及Na+,K+-ATP酶α1亚单位、PMCA1 mRNA表达均显著降低[Na+,K+-ATP:(4.3±0.8) μmol·h-1·mg-1比(5.3±1.0) μmol·h-1·mg-1,Ca2+-ATP酶:(3.2±0.7)μmol·h-1·mg-1比(4.5±0.7) μmol·h-1·mg-1,α1亚单位:0.524±0.025比0.704±0.116,PMCA1:0.193±0.030比0.547±0.045](P＜0.05～P＜0.01).ANP可增加SHR大鼠Na+,K+-ATP酶、Ca2+-ATP酶活性及Na+,K+-ATP酶α1,亚单位及PMCA1 mRNA表达(均P＜0.01),Ang Ⅱ则抑制Ca2+-ATP酶活性和PMCA1 mRNA表达(P＜0.05～P＜0.01),仅1×10-7 mol/L AngⅡ抑制Na+,K+-ATP酶活性及α1亚单位mRNA表达,ANP能拮抗AngⅡ对两种ATP酶活性及其mRNA表达的效应.ANP也能拮抗AngⅡ对WKY大鼠Ca2+-ATP酶活性及PMCA1mRNA表达的效应,对Na+,K+-ATP酶活性及α1亚单位mRNA表达无影响(P＞0.05).结论 高血压大鼠ASMC两种ATP酶活性和基因表达下降与局部ANP和AngⅡ分泌异常有关,ANP能拮抗AngⅡ对两种ATP酶活性和基因表达的效应.     

The influence of chloroethylclonidine-induced contraction in isolated arteries of Wistar Kyoto rats: alpha1D- and alpha1A-adrenoceptors, protein kinase C, and calcium influx.

BACKGROUND: It has recently been reported that chloroethylclonidine (CEC) elicited contraction in tail arteries (alpha(1A)-adrenoceptors) and aorta (alpha(1D)-adrenoceptors) from normotensive and spontaneously hypertensive rats (SHR). This study investigated the relationship between CEC-induced contraction and the role of protein kinase C (PKC) and extracellular Ca(++) influx in tail arteries and aorta from Wistar Kyoto rats (WKY). METHODS: Time-course of CEC-induced contraction in endothelium-denuded arteries from Wistar, WKY, and SHR rats was evaluated. In WKY arteries, calphostin C (1 x 10(-6) M) and nitrendipine (1 x 10(-6) M) were used to determine the role of PKC and extracellular Ca(+1) in the contractile response to CEC, respectively. RESULTS: Chloroethylclonidine (1 x 10(-4) M) elicited contraction in tail arteries and aorta from normotensive and hypertensive rats. Maximal response to CEC was similar in tail arteries among strains (approximately 30% of norepinephrine effect), while in aorta CEC elicited a higher contraction in WKY and SHR than in Wistar (59, 86, and 18% of norepinephrine effect, respectively). CEC-elicited maximal contractile responses were reached in 5 min in tail arteries and in 30-45 min in aorta irrespective of the rat strain, suggesting that different intracellular signaling pathways are involved in the contractile response to CEC in these arteries. In WKY tail arteries, calphostin C and nitrendipine blocked CEC-induced contraction while in aorta nitrendipine, but not calphostin C, inhibited CEC action. CONCLUSIONS: This study confirms marked strain-dependent differences in rat aorta responsiveness to CEC and suggests a central role for PKC in response to CEC in tail arteries and for extracellular Ca(+1) influx in aorta.