A Novel Angiotensin I Converting Enzyme Inhibitory Peptide from the Milk Casein:Virtual Screening and Docking Studies

Angiotensin I converting enzyme （ACE） plays an important physiological role in the regulation of hypertension. In this study, we applied virtual screening to discover a novel angiotensin I converting enzyme inhibitory peptides from milk casein. One potential hit was identified based on docking scores, subsequently confirmed by activity studies in vitro （IC50=20.85 μmol L-1）. The proposed peptide in this study contains a unique sequence, Lys-Val-Leu-Ile-Leu-Ala. Moreover, we performed the docking studies to understand the binding mode between the enzyme and peptide hit.

Drying Technology of Angiotensin Converting Enzyme Inhibitory Peptide Derived from Bovine Casein

Drying technology of angiotensin converting enzyme （ACE） inhibitory peptides derived from bovine casein was investigated. No significance was observed on ACE inhibitory activity of products prepared by spay drying and freeze drying （P〉0.05）. Spay drying was the best drying process for practical industry production. The inlet temperature ranged from 140℃ to 160℃ and the exit temperature ranged from 70 ℃ to 90 ℃ during the spay drying process. Under the optimal conditions, scale-up of angiotensin converted enzyme inhibitory peptide from 1 L to 10 L and the experiment was successively conducted. Peptide yield was 29% and half inhibitory concentration （IC50） was 0.53 g. L^-1.

Association of Polymorphisms in Angiotensin-converting Enzyme and Type 1 Angiotensin Ⅱ Receptor Genes with Coronary Heart Disease and the Severity of Coronary Artery Stenosis

To explore the relation of angiotensin-converting enzyme （ACE） and angiotensin Ⅱ type 1 receptor （AT1R） gene polymorphism with coronary heart disease （CHD） and the severity of coronary artery stenosis, 130 CHD patients who underwent coronary angiography were examined for the number of affected coronary vessels （≥75% stenosis） and coronary Jeopardy score. The insertion/deletion of ACE gene polymorphism and AT1R gene polymorphism （an A→C transversion at nucleotide position 1166） were detected by using polymerase chain reaction （PCR） and restriction fragment length polymorphism （RFLP） in CHD patients and 90 healthy serving as controls. The resuits showed that DD genotype and of ACE were more frequent in CHD patients than that in control group （38.5% vs 14.4%, P〈0.001）. The frequency of the ATIR A/C genotypes did not differ between the patients and the controls （10% vs 13.1%, P〉0.05）. The relative risk associated with the ACE-DD was increased by AT1R-AC genotype. Neither the number of affected coronary vessels nor the coronary score differed among the ACE I/D genotypes （P〉0.05）. But the number of affected coronary vessels and the coronary score were significantly greater in the patients with the AT1R-AC genotype than in those with the AA genotype （P〈0.05）. In conclusion, DD genotype may be risk factor for CHD and MI in Chinese people, and is not responsible for the development of the coronary artery stenosis. The AT1R-C allele may increase the relative risk associated with the ACE-DD genotype, and may be involved in the development of the stenosis of coronary artery.

Angiotensin Ⅰ-converting enzyme gene poly morphism in Chinese patientswith obstructive sleep apnea syndrome

Objective To investigate the relationship of an insertion/deletion (I/D) polymorphism of the angiotension converting enzyme (ACE) gene to obstructive sleep apnea syndrome (OSAS) patients and the control subjects.Methods Genomic DNA was extracted from blood samples and amplified by polymerase chain reaction (PCR). PCR primers flanked the polymorphic region in intro 16 of the ACE gene. Results OSAS patients had significantly higher frequencies of I/I genotype and insertion allele of the ACE gene as compared with the control subjects in Chinese population. The OSAS patients with I/I genotype had significantly longer apnea time, lower minimum SaO2 and greater AHI than the OSAS patients with I/D genotype. Conclusion These results indicate that the I/I genotype and I allele are a risk factor for OSAS in Chinese.

Pharmacophore-based structure optimization of angiotensin converting enzyme inhibitory peptide

Chemical feature based pharmacophore models were generated for an angiotensin converting enzyme(ACE) inhibitory peptide using the Discovery Studio 2.0 pharmacophore modeling approach. The pharmacophore hypothesis selected has five features(one negative ionizable region,one hydrogen bond donor,one hydrogen bond acceptor and two hydrophobic functional groups). Additionally,ACE inhibitory hexapeptide previously obtained from silkworm pupae protein was optimized to target the ACE based on the selected pharmacophore. The results suggest that tri-peptide(thr-val-phe) may be structural determinant of ACE activity. Docking studies further provided confidence for the validity of the selected pharmacophore model to perform structure optimization of the ACE inhibitory peptide.

富硒对纳豆菌发酵鹰嘴豆产血管紧张素转化酶抑制肽的影响

该研究将富硒能力较强的纳豆芽孢杆菌作为发酵菌种,鹰嘴豆为原料,以血管紧张素转化酶(angiotensin I converting enzyme,ACE)抑制率为指标,采用单因素试验和响应面优化法对纳豆芽孢杆菌富硒后产ACE抑制肽的最佳条件进行优化。同时采用超高效液相色谱-电喷雾电离-串联质谱(ultra performance liquid chromatography electrospray ionization tandem mass spectrometry,UPLC-ESI-MS/MS)法对鹰嘴豆纳豆富硒后硒代氨基酸进行定性定量分析。结果表明,L-硒代胱氨酸是鹰嘴豆纳豆富硒后主要的硒代氨基酸,纳豆芽孢杆菌富硒后产ACE抑制肽的最佳条件为接种量2%、液料比18∶1(mL/g)、发酵温度40℃,ACE抑制率可达89.24%。对比试验的结果显示,纳豆芽孢杆菌不富硒发酵鹰嘴豆产ACE抑制肽活性为66.35%,表明富硒纳豆芽孢杆菌发酵鹰嘴豆对ACE活性有良好的抑制作用。

Effects of angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor blockers on lymphangiogenesis of gastric cancer in a nude mouse model

Background Angiotensin-converting enzyme inhibitors （ACEI） and angiotensin II type 1 receptor blockers （ARB） can inhibit tumor growth by inhibition of angiogenesis. This study was designed to study the anticancer effects of ACEI and ARB on tumor growth and lymphangiogenesis in an implanted gastric cancer mouse model. Methods A model of gastric cancer was established by subcutaneously inoculating human gastric cancer cell line SGC-7901 into 60 nude mice. One week later, all mice were randomly divided into 5 groups. A control group received physiologic saline once daily for 21 days. Mice in the 4 treatment groups received one of the following agents by gavage once daily for 21 days： perindopril, 2 mg/kg; captopril, 5 mg/kg; Iosartan, 50 mg/kg; or valsartan, 40 mg/kg. Twenty-one days after treatment, all the mice were sacrificed and the tumors were removed. Tumor sections were processed, and immunohistochemical methods were used to observe the expressions of vascular endothelial growth factor C （VEGF-C）, matrix metalloproteinase 7 （MMP-7）, and lymphatic microvessel density （LMVD）. Results Tumor volume was significantly inhibited in all ACEI and ARB groups, compared with the control group （all P 〈0,01）. LMVD in the ACEI and ARB groups was also significantly lower than that of the control group （all P 〈0.01）. In the ACEI groups, the expressions of VEGF-C and MMP-7 were both significantly decreased, compared with the control group （all P 〈0.05）. In the ARB groups, expression of VEGF-C was significantly decreased compared with the control group （all P 〈0.05）. However, no significant difference was found in the expression of MMP-7 between ARB groups and the control group. Conclusion In a mouse model, ACEI and ARB might inhibit gastric cancer tumor growth by suppressing lymphangiogenesis.

槟榔籽提取物对血管紧张素转化酶(ACE)活性的抑制作用研究

以嫩果期槟榔籽为研究对象,采用75%乙醇浸提制得槟榔籽提取物(areca nut extract,ANE),再分别用石油醚、乙酸乙酯和正丁醇依次对总提取物进行萃取,依次得到嫩果期槟榔籽75%乙醇提取物的石油醚部位(PE-ANE)、乙酸乙酯部位(EAC-ANE)、正丁醇部位(BU-ANE)、水部位(W-ANE)的萃取部分。通过体外抑制血管紧张素转化酶(ACE)活性抑制试验测定槟榔提取物各极性部位对高血压的抑制潜力;通过酶动力学实验分析ACE抑制活性最好的极性部位对ACE活性的抑制作用类型;测定不同极性部位蛋白质、总糖及多酚的总含量,并分析其与ACE半抑制浓度(IC50)之间的相关性;最后对4种不同极性部位萃取物中的多酚组分进行初步定量。结果表明:嫩果期槟榔籽提取物各极性部位均具有一定的ACE抑制活性,其中EAC-ANE的ACE抑制活性最好。酶动力学实验表明,EAC-ANE对ACE活性的抑制作用类型为竞争与非竞争的混合型抑制。相关性分析表明,各极性部位ACE的IC50值与多酚、总糖及蛋白质含量均呈显著负相关,且与多酚含量之间具有极强相关性(r=‒0.912)。在4个极性部位中定量了儿茶素、L-表儿茶素、原花青素B2、原儿茶酸、槲皮素等多种多酚组分,且EAC-ANE中的相关多酚组分含量最高。综上所述,槟榔提取物具有一定的降血压潜力,且乙酸乙酯萃取部位最好,多酚含量与各萃取部位的ACE抑制活性具有极强的相关性,可初步推断多酚是槟榔提取物中抑制ACE活性的重要物质。

红毛藻血管紧张素转化酶抑制肽的筛选及其稳定性评价

本实验以红毛藻为原料,利用酶解法及超滤分级制备获得不同分子质量的肽组分,经高效液相色谱法测定体外血管紧张素转化酶(angiotensin-converting enzyme,ACE)抑制活性发现F2组分(800~2000 Da)的ACE抑制率最高;采用液相色谱-串联质谱技术和PEAKS Studio软件的de novo从头测序对F2组分进行氨基酸序列鉴定,并结合分子对接筛选出与ACE稳定结合的6个ACE抑制肽。利用固相合成法制备预测肽并经体外ACE抑制活性验证,发现L1(LVLLFLFGE)的ACE抑制活性最高,半抑制浓度(half maximal inhibitory concentration,IC_(50))为14.22μg/mL。分子对接结果表明,L1对ACE的抑制主要归因于其能够与ACE的活性口袋形成氢键相互作用。最后,探讨温度、pH值、金属离子、光照类型和模拟胃肠道酶系消化对L1稳定性的影响,结果表明L1具有较好的热稳定性和离子强度稳定性,pH>2时抑制活性逐步减弱,紫外光处理会影响其抑制活性,体外模拟胃肠液处理后L1的ACE抑制率虽然显著降低,但仍具有较高ACE抑制活性。

三种描述符对食源性血管紧张素转化酶抑制二肽定量构效关系研究

为探究血管紧张素转化酶(angiotensin converting enzyme,ACE)抑制肽结构与功能的关系,阐明食源性ACE抑制肽作用机理,该文收集最近报道的血管紧张素转化酶抑制二肽的氨基酸序列及其IC_(50)值,用Z-scales、VHSE和SVHEHS三种氨基酸描述符对ACE抑制二肽的结构进行表征,以氨基酸的疏水性质、立体性质以及电性性质参数作为自变量,ACE抑制二肽的lg(IC_(50))作为因变量,建立ACE抑制二肽的定量构效模型。结果显示基于Z-scales描述符建立的二肽定量构效模型R^(2)为0.8477,Q^(2)为0.8284,模型预测二肽Phe-Phe有较高的ACE抑制活性,预测IC_(50)为1.0499μmol/L,实测IC_(50)为(1.0414±0.0041)μmol/L,预测值与实测值误差为0.0085μmol/L。基于VHSE描述符构建的模型R^(2)为0.8568,Q^(2)为0.8052,模型预测二肽Asp-Trp有较高的ACE抑制能力,预测IC_(50)为1.2160μmol/L,实测IC_(50)为(1.1100±0.0053)μmol/L,误差为0.1060μmol/L。基于SVHEHS描述符构建的定量构效模型R^(2)为0.8581,Q^(2)为0.7453μmol/L,模型预测二肽Ala-Trp有较高的ACE抑制活性,预测IC_(50)为1.0323μmol/L,实测IC_(50)为(1.1290±0.0082)μmol/L,误差为0.0967μmol/L。3种氨基酸描述符均能较为合适地对ACE抑制二肽进行定量构分析。通过模型分析发现ACE抑制肽C端氨基酸残基疏水特性和立体特征与其活性关系更为密切,其氨基酸残基的疏水特征和立体特征越强,ACE抑制肽的活性越强。通过3种ACE抑制二肽与ACE蛋白(2X8 J)进行分子对接发现,3种ACE抑制肽均可与ACE蛋白进行结合。表明通过偏最小二乘法对Z-scales、VHSE、SVHEHS三种描述符对ACE抑制二肽构建定量构效关系模型是可行的。这将对ACE抑制肽的检测、预测和筛选具有积极的意义。

药食同源物协同血管紧张素转化酶抑制肽微胶囊的制备及其降压作用

研究药食同源复合物(枸杞∶山楂∶决明子=4∶1∶1,质量比,下同)协同血管紧张素转化酶(angiotensin convertingenzyme,ACE)抑制肽微胶囊对自发性高血压大鼠(spontaneouslyhypertensiverats,SHR)的降压作用。当ACE抑制肽与复合物的质量之比为1∶2时,ACE抑制率为78.19%,显著高于单一药食同源复合物(69.46%)及ACE抑制肽(71.48%)(P<0.05)。通过优化包埋工艺(固含物为10%、进风温度为160℃、芯壁比为1∶15、壁材为变性淀粉∶麦芽糊精=1∶4)制备药食同源物协同ACE抑制肽微胶囊包埋率为82.76%,在肠道中消化240 min后的释放率为81.4%,苦味显著降低(P<0.05)。动物实验结果发现药食同源物协同ACE抑制肽能够明显降低SHR的血压值,显著增加大鼠血浆中ACE2及血管紧张素1-7含量,降低血浆中ACE及血浆、心脏、肾脏及胸主动脉中血管紧张素II的含量(P<0.05),作用效果优于单一复合物及ACE抑制肽,证明药食同源物与ACE抑制肽存在协同效果,可通过调节肾素-血管紧张素系统降压,还可显著降低SHR心脏及胸主动脉纤维程度,从而改善由高血压引起的脏器损伤。

青刺果ACE抑制肽的分离纯化、结构鉴定及其体外活性评价

以具有血管紧张素转化酶(ACE)抑制活性的青刺果蛋白酶解物为研究对象,采用超滤、强阴离子交换层析分离纯化ACE抑制肽,液相色谱-串联质谱鉴定其肽序列。采用傅里叶红外光谱、酶反应抑制剂动力学、MTT试验和分子对接技术解析其二级结构特征、体外活性以及与ACE的结合机制。结果表明,分子质量<3 ku的超滤组分活性较好(IC50=0.380 mg/mL),离子交换层析后以F-a组分活性最好(IC50=0.159 mg/mL)。质谱鉴定出4条肽序列,通过生物信息学分析确定肽PGDVF为潜在的ACE抑制肽[IC50=(0.56±0.1)mmol/L]。二级结构分析表明PGDVF由α-螺旋(20.28%)、β-折叠(6.21%)、β-转角(31.55%)和无规则卷曲(41.85%)构成,其抑制模型为非竞争性抑制,肽质量浓度小于1 mg/mL时,对HepG2细胞无毒性。分子对接显示PGDVF可通过氢键、疏水作用与ACE紧密结合,从而有效抑制ACE活性。研究结果可为青刺果降压肽的开发利用提供参考。

基于氨基酸描述符对血管紧张素转化酶抑制五肽定量构效关系分析

本研究收集近些年报道的血管紧张素转化酶(angiotensin converting enzyme,ACE)抑制五肽的氨基酸序列及抑制活性(半抑制浓度(half maximal inhibitory concentration,IC_(50))),建立ACE抑制五肽肽库,并将其氨基酸残基用Z-scales、VHSE和SVHEHS氨基酸描述符分别进行表述,以氨基酸残基的疏水性、立体性以及电性参数作为自变量,ACE抑制五肽的lg IC_(50)作为因变量,利用Matlab软件用偏最小二乘法建立ACE抑制肽定量构效关系(quantitative structure-activity relationship,QSAR)模型,结果发现基于Z-scales描述符构建的ACE抑制五肽QSAR模型R2为0.6411,Q^(2)为0.5369,模型预测五肽Gln-Arg-Pro-Asn-Met具有较高的ACE抑制活性,预测IC_(50)为0.0517μmol/L,实测IC_(50)为(0.0400±0.0083)μmol/L,预测值与实测值误差为0.0117μmol/L;基于VHSE描述符构建的QSAR模型R2为0.7636,Q^(2)为0.5081,模型预测五肽Leu-Arg-Ala-Phe-Gln具有较高的ACE抑制活性,预测IC_(50)为0.0438μmol/L,实测值为(0.0273±0.0053)μmol/L,误差为0.0165μmol/L;基于SVHEHS描述符构建的QSAR模型R2为0.8405,Q^(2)为0.4005μmol/L,模型预测五肽Tyr-Phe-Pro-Phe-Gln具有较高的ACE抑制活性,预测值为0.0055μmol/L,实测值为(0.0312±0.0042)μmol/L,误差为0.0257μmol/L。3种建模方法对比发现,基于SVHEHS描述符构建的模型拟合能力最强,但是其预测能力较弱,而Z-scales和VHSE描述符所建模型能很好地对五肽进行QSAR分析,通过模型分析发现ACE抑制肽活性与其氨基酸的疏水特征呈负相关,与立体特征呈正相关。将3种ACE抑制肽与ACE蛋白(2X8J)进行分子对接,结果表明3种ACE抑制肽均可与ACE蛋白进行结合。本研究可为开发ACE抑制肽药物提供新手段,为开发和利用食源性ACE抑制肽提供理论基础。

菜籽肽的制备及其对大鼠血管紧张素Ⅰ转换酶(ACE)活性的影响(英文)

目的:分离菜籽清蛋白水解物并研究混合肽及级分对大鼠血管紧张素Ⅰ转换酶(ACE)活性的影响。方法:采用葡聚糖凝胶过滤色谱(SephadexG-25)分离菜籽肽;离体培养检测血管紧张素Ⅰ转换酶(ACE)活性。结果:菜籽肽(RSP-R)及分离的三个级分(RSP-Ⅰ、Ⅱ和Ⅲ)对高血压大鼠ACE活性均有明显抑制作用,其中级分Ⅲ抑制能力最强。结论:菜籽清蛋白水解多肽具有抑制ACE活性能力,这一结果有助于菜籽清蛋白的广泛应用。

血管紧张素Ⅰ转换酶、血浆纤溶酶原激活物抑制剂基因多态性与2型糖尿病肾病相关性分析

目的探讨血管紧张素Ⅰ转换酶（ACE）、血浆纤溶酶原激活物抑制剂（PAI-1）基因多态性与2型糖尿病肾病的相关性。方法58例健康者为对照组、92例糖尿病非肾病患者为糖尿病非肾病组、125例糖尿病肾病患者为糖尿病肾病组，聚合酶链反应确定ACE、PAI-1基因型。酶联免疫吸附法检测血浆PAI-1。结果糖尿病肾病组ACE基因中D等位基因频率、PAI-1基因中4G等位基因频率明显高于糖尿病非肾病组、对照组。Logistic回归分析表明ACE、PAI-1基因是2型糖尿病肾病的危险因素。结论ACE基因中D等位基因、PAI-1基因中4G等位基因可能涉及2型糖尿病肾病发病。

血管紧张素Ⅰ转换酶基因插入/缺失多态性与中国汉族2型糖尿病人群肾病发病风险相关性的Meta分析

目的评价血管紧张素Ⅰ转换酶(ACE)基因插入/缺失(I/D)多态性与中国汉族2型糖尿病人群发生肾病风险的相关性。方法由两名评价者独立采用计算机检索中国生物医学文献数据库、中国期刊全文数据库、中文科技期刊全文数据库和万方数据库中的ACE基因I/D多态性与糖尿病肾病(DN)的病例对照研究,检索时间范围均为1994-01-01—2011-03-10。对符合纳入标准的研究进行纳入研究质量及数据提取后,采用RevMan5.1.6软件进行Meta分析。结果共纳入24项病例对照研究,共3 206例患者。Meta分析结果显示,中国汉族人群携带至少1个I等位基因可以降低38%的DN发生风险〔OR=0.62,95%CI(0.52,0.75),P<0.00001〕;携带含有I等位基因的基因型能够使发生DN的风险降低45%〔OR=0.55,95%CI(0.44,0.69),P<0.00001〕;携带含有D等位基因的基因型能够使发生DN的风险增加1.74倍〔OR=1.74,95%CI(1.30,2.31),P=0.0002〕。敏感性分析表明结果稳健性均较好。结论 ACE基因I/D多态性与中国汉族2型糖尿病人群肾病易感性密切相关,D等位基因可能是易感基因,I等位基因可能是保护基因,但仍需进一步论证。

冠心病患者血管紧张素Ⅰ转换酶基因多态性分析

目的探讨血管紧张素Ⅰ转换酶(ACE)基因的单核苷酸多态性(SNP)与冠心病(CAD)的相关性。方法提取192例CAD患者和189例健康对照者外周血白细胞DNA,应用荧光标记单碱基延伸技术及杂交技术检测ACE基因的2个标签SNP rs4353和rs4305。结果 CAD组rs4353的GG基因型和rs4305的AA基因型频率明显高于健康对照组(P<0.05)。2个SNP的等位基因频率在两组间无统计学差异(P>0.05)。通过对rs4353和rs4305进行单倍型分析发现,CAD组和健康对照组的AG单倍型频率具有统计学差异(P<0.05)。结论 ACE基因rs4353和rs4305多态性变异及其构建的AG单倍型是CAD的遗传危险因素。

急性冠脉综合征患者血清ACE2、suPAR水平与氧化应激损伤及不良预后的关系

目的 探讨急性冠脉综合征(Acute coronary syndrome, ACS)患者血清血管紧张素转化酶2(Angiotensin converting enzyme 2,ACE2)、可溶性尿激酶型纤溶酶原激活物受体(Soluble urokinase type plasminogen activator receptor, suPAR)与氧化应激损伤及不良预后的关系。方法 选择2019年9月-2022年9月大兴区人民医院收治的125例ACS患者作为ACS组,并选取与之性别、年龄相匹配的50例冠脉造影结果完全正常者作为对照组,比较两组血清ACE2、suPAR及氧化应激指标[丙二醛(Malondialdehyde, MDA)、过氧化脂质(Lipid peroxide, LPO)、超氧化物歧化酶(Superoxide dismutase, SOD)]水平,并分析血清ACE2、suPAR与氧化应激、不良预后的关系。结果 与对照组比较,ACS组ACE2、suPAR、MDA、LPO升高(P<0.05),SOD下降(P<0.05)。轻度病变、中度病变、重度病变患者ACE2、suPAR及冠脉狭窄Gensini评分显著上升(P<0.05)。ACS患者ACE2、suPAR与MDA、LPO、Gensini评分呈正相关(P<0.05),与SOD呈负相关(P<0.05)。与预后良好患者比较,预后不良患者年龄、发病至就诊时间、Gensini评分、ACE2、suPAR、MDA、LPO升高(P<0.05),LVEF、SOD降低(P<0.05)。年龄、发病至就诊时间、Gensini评分、ACE2、suPAR、MDA、LPO是ACS预后不良的危险因素(P<0.05),LVEF、SOD为其保护因素(P<0.05)。血清ACE2联合suPAR预测ACS预后不良的效能较高,其曲线下面积(Area under curve,AUC)为0.894。结论 ACS患者血清ACE2、suPAR高表达与氧化应激损伤、不良预后显著相关。

血管紧张素Ⅰ转换酶抑制剂的合成及生理活性研究

用多肽固相合成法合成了血管紧张素Ⅰ转换酶抑制剂(ACEI),经HPLC检查其纯度达99%以上,用质谱测得分子量与理论值相同,氨基酸组分分析与预期结果相一致。动物实验表明,在体外ACEI对大鼠的ACE有明显的抑制作用;在体内能有效地降低血压。

缺氧下冻伤对大鼠血清血管紧张素Ⅰ转换酶活性的影响

实验观察了在模拟海拔６０００ｍ缺氧冻伤对大鼠血清血管紧张素Ⅰ转换酶（ＡＣＥ）活性的影响。大鼠血清ＡＣＥ活性以Ｕ（ｎｍｏｌ·ｍｌ－１·ｍｉｎ１）表示。致冻前，缺氧习服缺氧冻伤（ＦＨＡＣ）组和急性缺氧冻伤（ＦＡＨ）组大鼠血清ＡＣＥ活性分别为５０．０±５．８和６０．０±６．７Ｕ（Ｐ＞０．０５）明显低于平原冻伤（ＦＮ）组的７８．１±４．０Ｕ（Ｐ＜０．０１和Ｐ＜０．０５）；冻后４ｈ，ＦＡＨ组和ＦＨＡＣ组大鼠血清ＡＣＥ活性均呈现较冻前增高趋势；冻后２４ｈ，ＦＡＨ组与冻前无差异，而ＦＨＡＣ组冻后７２ｈ仍呈增长趋势。结果表明：单纯缺氧暴露可使大鼠血清ＡＣＥ活性降低，而缺氧复合冷损伤则使大鼠血清ＡＣＥ活性呈现增高趋势，提示可能有内皮细胞损伤。