福辛普利、卡托普利及缬沙坦对人血单核细胞表达组织因子的影响

目的:研究血管紧张素转换酶抑制剂(ACEI)中的福辛普利(fosinopril)、卡托普利(captopril)及I型血管紧张素II受体拮抗剂(ARB)中缬沙坦(valsartan)对人血单核细胞受细菌脂多糖(LPS)刺激表达组织因子(TF)的影响。方法:从健康平产妇脐静脉取得脐血,分离单个核细胞,分组培养,以LPS(0.1 mg/L)刺激作为对照组,其它组分别再加入ACEI类药物fosinopril (20 mg/L)、captopril(20 mg/L)及valsartan(20 mg/L),孵育。冻融法收集细胞裂解液,用一期凝固法分析LPS诱导单核细胞表达的组织因子促凝活性。用RT-PCR技术,观察各组表达TFmRNA,并以GAPDH作为内参照进行半定量分析。结果和结论:Fosinopril,captopril及valsartan可下调人血单核细胞由LPS诱导的TFmRNA的表达,并显著降低促凝活性。     

Glial fibrillary acidic protein (GFAP) immunochemical profile after Junin virus infection of rat cultured astrocytes

After five steps of purification including gel permeation, anti-angiotensin I affinity column chromatography followed by reverse-phase HPLC, a peptide immunoreactive to two different antisera (anti-angiotensin I) was purified to homogeneity from extracts of the leech Theromyzon tessulatum. The first 14 amino acid residues of the purified peptide (DRVYIHPFLLXWG) established by automated Edman degradation, reveal the existence in leeches of an angiotensin I-like molecule close to human angiotensin I. The sequence of the purified peptide presents 78.5% of homology with the N-terminal part of human angiotensin. Moreover, in its sequence, this peptide presents the cleavage sites of vertebrate angiotensin metabolic enzymes, i.e. the renin and the angiotensin-converting enzyme. This finding constitutes the first biochemical characterization of an angiotensin I in Invertebrates. It also reflects the high conservation of angiotensins in the course of evolution, suggesting a fundamental role of this family in fluid homeostasis.     

血管紧张素-(1-7)对血管紧张素Ⅱ诱导心肌细胞原癌基因c-fos表达的影响

目的　探讨血管紧张素 - (1- 7) [Ang- (1- 7) ]对血管紧张素 (Ang )诱导心肌细胞原癌基因 c- fos表达的影响。方法　在 Ang 诱导培养的新生 SD大鼠心肌细胞中应用 Ang- (1- 7) ,用 TRIzol试剂法提取心肌细胞总 RNA,用特异性 c- fos引物 (GAPDH作内参 )和 Super Script一步法 RT- PCR试剂盒进行逆转录 -聚合酶链式反应 ,RT-PCR产物在琼脂糖凝胶上电泳 ,用 GSD凝胶成像系统拍摄打印 ,条带用计算机图像分析系统扫描定量。结果　 Ang 作用心肌细胞 3 0 min后 ,心肌细胞原癌基因 c- fos表达较对照组 c- fos表达明显增加 (P<0 .0 1) ,而当用 Ang- (1- 7)与 Ang 联合作用时 ,Ang 诱导心肌细胞 c- fos基因表达作用明显受到抑制 (P<0 .0 1)。予 A- 779预处理后 ,Ang- (1- 7)抑制 Ang 诱导的心肌细胞原癌基因 c- fos的表达作用消失 ,而 A- 779其本身对心肌细胞原癌基因 c- fos表达无明显影响。结论　 Ang- (1- 7)可抑制 Ang 诱导的心肌细胞原癌基因 c- fos的表达 ,其作用能被A- 779阻断     

血管紧张素-（1-7）抑制肾小球系膜细胞增殖过程中c-fos蛋白表达

目的观察血管紧张素-（1-7）[Ang-（1-7）]对血管紧张素-Ⅱ（Ang-Ⅱ）诱导的肾小球系膜细胞（GMC）增殖过程中c-fos表达的影响。方法体外培养GMC，Ang-Ⅱ为刺激因子，不同浓度Ang-（1-7）为干预因子。用结晶紫计数法检测GMC数目的变化；Western blot检测GMC中c-fos蛋白表达的变化。结果Ang-（1-7）呈剂量依赖性地抑制Ang-Ⅱ诱导的GMC增殖和GMC内c-fos蛋白表达。结论Ang-（1-7）可能通过抑制c-fos的表达，抑制Ang-Ⅱ诱导的GMC增殖。     

缬沙坦与贝那普利联用治疗移植肾慢性损伤的远期效果

目的 探讨血管紧张素受体拮抗剂缬沙坦与血管紧张素转化酶抑制剂贝那普利联合应用治疗肾移植患者移植肾慢性损伤的远期效果. 方法非糖尿病患者肾移植术后尿蛋白＞0.5g/d或SCr＞177 mmol/L(＞2 mg/d)32例,随机分2组:①治疗组23例.男9例,女14例.平均40岁.病理诊断慢性移植物肾病(CAN)13例、环孢素中毒3例、肾小球疾病7例.②对照组9例.男4例,女5例.平均35岁.CAN 6例、环孢素中毒1例、肾小球疾病2例.治疗组给予缬沙坦(80mg/d)与贝那普利(20 mg,2次/d)联合治疗3年,对照组未进行此项处理.比较2组患者治疗前后SCr、24 h尿蛋白变化及移植肾生存时间.结果 随访3年后,治疗组SCr为(252.2±117.9)mmol/L,对照组为(375.3±203.0)mmol/L,2组比较差异有统计学意义(P＜0.05).治疗组CAN患者SCr为(282.4±147.3)mmol/L,对照组为(528.7±107.8)mmol/L,2组比较差异有统计学意义(P＜0.01).治疗组24 h尿蛋白为(1.0±0.6)g,对照组为(1.3±0.7)g,组问差异无统计学意义(P＞0.05).移植肾存活时间治疗组76个月,对照组为71个月,组间差异无统计学意义(P＞0.05).结论 缬沙坦与贝那普利联合应用可保护移植肾功能,对蛋白尿及移植肾远期存活的影响有待进一步观察.     

Genetics of Angiotensin I-Converting Enzyme

The ACE gene is constitutively expressed in several types of somatic cells, including vascular cells. A soluble form of the enzyme is secreted in plasma by proteolytic cleavage of the membrane anchor. The interindividual variability in plasma ACE levels is very large, and a family study has indicated that it was under the influence of a major gene polymorphism. An insertion (I) deletion (D) polymorphism in intron 16 of the ACE gene was then found to be associated with plasma and cellular ACE levels. The D allele, wich is associated with higher plasma ACE levels, and the level of ACE in plasma, were found in case control studies to be associated with an increased risk of myocardial infarction, an increased risk of diabetic nephropathy in type I diabetic patients, and a faster rate of renal function degradation in glomerular diseases. Although these findings should be confirmed in prospective studies, they can support the concept that ACE level is a critical factor in the determinism of angiotensins and kinins (and perhaps also other peptide substrates) levels in peripheral circulations and in tissue interstitium, especially in the heart and kidney.     

曲美他嗪对大鼠心力衰竭模型心功能及神经激素的影响

目的 探讨盐酸曲美他嗪对慢性心力衰竭(CHF)大鼠模型心功能和神经激素的影响.方法 腹主动脉缩窄法制备SD大鼠心衰模型,心脏超声测定室间隔(IVS)及左室后壁(LVPW)厚度、左室舒张末期内径(LVD)和收缩末期内径(LVS)、左室射血分数(LVEF)和短轴缩短率(FS);观察心肌细胞病理变化;Real-Time PCR定量测定神经激素尿钠肽(BNP)、C型心钠肽受体(NPRC)、心钠肽(ANP)、肌球蛋白重链(β-MHC)、血管紧张素1(AT1);免疫组化测定超氧化物歧化酶(SOD).结果 曲美他嗪高剂量组和模型组比较,IVS、LVPW、LVS、LVD分别为(0.63 ±0.05)mm、(0.73 ±0.06) mm、(0.73±0.05) nn、(0.87±0.06) mm和(1.07 ±0.06)mm、(1.13±0.06)mm、(0.93±0.06) mm、(1.33 ±0.06)mm(P ＜0.05);LVEF、FS分别为(27.75±1.83)％、(11.44±0.76)％和(11.78±0.56)％、(4.27±0.22)％(P＜0.01);心肌细胞结构明显改善;B NP、ANP、NPRC、ATI、β-MHC表达下降,SOD表达升高.结论 曲美他嗪能改善大鼠心衰模型神经激素的分泌,改善心功能.     

血管紧张素-(1-7)对心肌肥厚的影响及其与细胞外信号调节激酶的关系

目的：探讨血管紧张素-(1-7)［Ang-(1-7)］对压力负荷性心肌肥厚的影响及其与细胞外信号调节激酶1/2(ERK1/2)的关系。 方法： 采用腹主动脉缩窄术复制心脏压力负荷增高大鼠模型。75只SD大鼠随机分为假手术组、模型对照组、Ang-(1-7)治疗组。在腹主动脉缩窄术后1 d开始，Ang-(1-7)治疗组大鼠，经置入式微量泵持续颈静脉给予Ang-(1-7) (25 μg·kg-1·h-1)；假手术组及模型对照组经微量泵只给予同量的生理盐水。各组分别于术后1周、术后4周处死部分大鼠，检测左心室重量/体重比、血浆及心肌血管紧张素Ⅱ浓度，并采用免疫印迹方法检测大鼠心肌中磷酸化ERK1/2(p-ERK1/2)表达水平。 结果： 术后1周和4周，腹主动脉缩窄均导致心肌血管紧张素Ⅱ浓度升高、左心室重量/体重比增加，也导致了心肌中p-ERK1/2表达增高；血管紧张素-(1-7)治疗未改变腹主动脉缩窄对心肌血管紧张素Ⅱ浓度的影响，但能明显减轻腹主动脉缩窄所诱导增高的左心室重量/体重比和心肌中p-ERK1/2表达水平。 结论： 外源性Ang-(1-7)可减轻压力负荷增高所致的心肌肥厚，这一作用可能与它抑制心肌p-ERK1/2表达有关。     

血管活性物质对人内皮细胞C-型利钠利尿肽合成和释放的影响

目的:在培养的人内皮细胞上观察内皮素(ET)、血管紧张素Ⅱ(AngⅡ)和同型半胱氨酸(Hcy)对C-型利钠利尿肽(CNP)生成和释放的影响,以探讨CNP生成和释放的机制。方法:人内皮细胞培养;CNP放免测定。结果:ET、AngⅡ均可刺激内皮细胞CNP的生成,10^-9、10^-8、10^-7mol/L的ET和AngⅡ分别使细胞CNP含量较对照组高1%(P＞0.05),49%(P＜0.05),117%(P＜0.01)和137%(P＜0.01),165%(P＜0.01),201%(P＜0.01),大剂量ET、AngⅡ可刺激CNP的释放。Hcy对内皮细胞CNP的生成没有影响,但10 ^-9、10^-8、10^-7mol/LHcy可使其释放增加17%(P＞0.05),84%(P＜0.01)和555%(P＜0.01)。结论:ET、Ang和Hcy可调节CNP的释放和/或生成。     

Binding of angiotensins to rat brain tissue: Structure activity relationship

The binding of ³H-angiotensin II to a synaptosome-enriched fraction of the subcortical part of rat brain was studied. In this fraction specific high-affinity binding sites for angiotensin II were demonstrated. The binding sites were saturated at a ligand concentration of 2×10⁻⁹ M. Scatchard analysis revealed a single class of binding sites with an apparent maximal binding capacity of 14 fmoles/mg of protein and an equilibrium dissociation constant, K_d, of 0.9 × 10⁻⁹ M. The specific binding at the K_d concentration amounted to 59% of the total binding and was reversible. The association and dissociation rate constants (k₁ and k₋₁) were 0.0212 nM⁻¹ min⁻¹ and 0.0196 min⁻¹, respectively. Binding was dependent on both incubation time and tissue concentration in the incubation mixture. Angiotensins with biological activity in the brain, i.e., angiotensins I, II, III, and the fragments (3–8) and (4–8) competed with ³H-angiotensin II for the binding sites with IC₅₀'s of 9×10⁻⁸ M, 2×10⁻⁹ M, 4× 10⁻⁹ M, 4× 10⁻⁷ M and 4×10⁻⁶, respectively. In the presence of 1 mM of the converting enzyme inhibitor SQ 14,225 the IC₅₀ for angiotensin I was 2 × 10⁻⁷ M. Competition by the biologically active fragment angiotensin (5–8) could not be demonstrated. The latter peptide, however, was highly metabolized during the incubation under the assay conditions used. The binding potency of the various angiotensins paralleled their dipsogenic and presser potency. The present data indicate the possible physiological involvement of these binding sites as specific receptors in the actions of angiotensins in the brain.