微粒体环氧水解酶与相关疾病的研究进展

微粒体环氧水解酶（microsomal epoxide hydrolase，EPHX1）是一种进化高度保守的生物转化酶，基因编码提示其具有遗传多态性，因此EPHX1基因有多种单核苷酸多态性（single nucleotide polymorphism，SNP），其中有2种常见SNP（rs1051740与rs2234922）可以导致酶活性发生变化。EPHX1在功能上还具有广泛的底物选择性，可生物活化胆固醇等多种底物，并参与异源物质的代谢以达到解毒的作用，还可通过催化作用激活多环芳烃的致癌性而诱发癌变。因此，EPHX1基因结构、分布、多态性、生理功能与人类多种疾病息息相关。本文将对EPHX1基因及与之相关疾病的关键点总结归纳，为EPHX1基因进一步研究提供参考。     

基因芯片法检测中国人乙醛脱氢酶2的基因多态性

摘 要 目的： 对中国人乙醛脱氢酶2（ALDH2）的基因多态性进行检测,指导临床硝酸甘油的合理用药。方法: 采用显色基因芯片方法测定ALDH2基因（Glu504Lys）多态性。结果:对1 026例中国人群临床样本的检测,获得3种基因型,分布频率为：ALDH2（504Glu）野生纯合子61.7%(623例),ALDH2（Glu 504Lys）杂合子31.6%(319例),ALDH2（504Lys）突变纯合子6.6%(67例)。结论: 中国人群对硝酸甘油无效概率高的患者大约占1/3。本文建立的检测方法适合医院开展常规临床指导用药的基因检测。     

基因多态性与糖皮质激素诱导性股骨头坏死的相关性meta分析

目的 应用meta分析证实靶基因的多态性是否与糖皮质激素诱导性股骨头坏死（steroid-induced osteonecrosis of the femoral head,SONFH）发生相关。方法 检索PubMed、Embase、The Cochrane Library、Clinical Trial、CBM、万方、维普和CNKI等数据库中已发表的文章以获得适宜的研究,并以固定或者随机效应模型计算最终的OR值和95%置信区间（95%CI）。结果 检索共发现有37项研究包含41个与SONFH发生风险相关的基因多态性位点。选择含有≥3个适宜研究的多态性位点进入meta分析,纳入的多态性位点主要集中在3个基因即PAI-1、MTHFR和ABCB1。携带有PAI-1突变基因5G的患者应用糖皮质激素后易发生SONFH,但差异不具有统计学意义[OR=0.95,95%CI（0.54,1.67）,P=0.85]。SONFH发生率在MTHFR突变型和野生型之间差异存在统计学意义[OR=0.69,95%CI（0.50,0.95）,P=0.02],携带有MTHFR 677T的患者较易发生SONFH。携带ABCB1 3435C等位基因者发生SONFH的风险更高,具有显著的统计学差异[OR=1.40,95%CI（1.11,1.76）,P=0.005];而ABCB1 G2677T/A位点的基因多态性与SONFH发生之间无明显的统计学差异[OR=1.32,95%CI（0.76,2.28）,P=0.32]。结论 MTHFR C677T和ABCB1 C3435T基因的多态性与股骨头坏死的发生风险显著相关。     

UGT1A1基因多态性对药物代谢和临床作用影响的进展

UGT1A1基因是参与人体代谢循环的重要基因,随着药物基因组学的发展,发现其基因多态性与某些药物代谢水平相关,进而影响疾病的发生、发展及治疗等诸多方面。随着研究进展,UGT1A1的底物在不断扩展,包括胆红素、雌激素、伊立替康及其他一些药物已有研究。研究UGT1A1基因多态性对药物代谢情况的影响,在临床疾病的诊治、预后判断及药物不良反应等方面有重要的指导意义。     

5-HTR2A 102T>C基因多态性与抗精神病药物疗效的Meta-分析

目的 系统评价5-HTR2A 102T>C基因多态性与抗精神病药物疗效的相关性。方法 计算机检索Web of Science、PubMed、中国学术期刊全文数据库（CNKI）、万方数据库、维普数据库中研究5-HTR2A 102T>C基因多态性与抗精神病药物疗效的研究,检索年限从建库至2017年5月2日。按纳入与排除标准筛选文献、提取资料并评价纳入研究的方法学质量后,采用Stata 12.0软件进行Meta分析。结果 共纳入10项研究,Meta-分析结果表明,5-HTR2A 102T>C基因多态性与抗精神病药物疗效在等位基因模型、共显性基因模型、显性基因模型中均无统计学意义（P>0.05）：等位基因模型OR=1.16,95% CI（1.00~1.36）;共显性基因（TT vs CC）模型OR=1.23,95% CI（0.91~1.65）;共显性基因（TT vs TC）模型OR=0.90,95% CI（0.68~1.19）;显性基因模型OR=1.04,95% CI（0.80~1.34）;而隐性基因模型和超显性基因模型具有统计学意义（P<0.05）：隐性基因模型OR=1.37,95% CI（1.09~1.72）;超显性基因模型OR=0.78,95% CI（0.62~0.96）。结论 5-HTR2A 102T>C基因多态性与抗精神病药物疗效有关联性。     

VKORC1-3673G>A、CYP2C9*3、CYP4F2 rs2108622和CYP2C19*2基因多态性对中国汉族房颤患者华法林维持剂量的影响

目的 探讨VKORC1-3673G>A、CYP2C9^*3、CYP4F2 rs2108622和CYP2C19^*2位点基因多态性对中国汉族房颤患者华法林维持剂量的影响。方法 收集107例服用华法林达维持剂量的汉族房颤患者的血样和临床相关资料,应用PCR-RFLP法检测VKORC1-3673G>A、CYP2C9^*3、CYP4F2 rs2108622和CYP2C19^*2基因型,采用独立样本t检验分析基因型与华法林维持剂量的相关性。多元线性回归建立给药模型,探讨基因多态性对华法林维持剂量的影响。结果 VKORC1-3673G>A、CYP2C9^*3、CYP4F2 rs2108622基因多态性和患者年龄、体质量能解释45.2%的华法林维持剂量差异。CYP2C19^*2基因多态性对本研究人群华法林维持剂量无影响。结论 VKORC1-3673G>A、CYP2C9^*3、CYP4F2 rs2108622基因多态性显著影响中国汉族房颤患者的华法林维持剂量。     

PLA2R基因多态性与成人特发性膜性肾病治疗效果及预后的关系

目的 探讨磷脂酶A2受体(PLA2R)SNP rs35771982位点基因多态性与成人特发性膜性肾病(IMN)治疗效果及预后的关系。方法 选取2017年1月至2018年12月新疆维吾尔自治区人民医院肾内科确诊的60例IMN患者为IMN组,选取同期60例健康体检者作为对照组,比较两组研究对象PLA2R基因单核苷酸多态性(SNP)rs35771982位点的基因型,比较不同基因型IMN患者完全/部分缓解率、复发率、不良反应发生情况,采用二元logistic回归分析PLA2R基因不同基因型与成人IMN患者预后的关系。结果 IMN组患者PLA2R基因SNP rs35771982位点存在GG、GC、CC 3个基因型,GG基因型、G等位基因比例显著低于对照组,CC基因型、C等位基因比例显著高于对照组(P<0.05);CC基因型患者的完全/部分缓解率显著低于GC、GG基因型患者(P<0.05);CC基因型患者的复发率显著高于GC、GG基因型患者(P<0.05);CC基因型患者的血糖异常率显著高于GG基因型患者(P<0.05);CC基因型患者的尿酸异常率显著高于GG、GC基因型患者(P<0.05);logistic回归分析显示,CC基因型是影响IMN患者不良预后的危险因素(OR=6.634, P<0.05)。结论 新疆维吾尔族自治区人群PLA2R基因SNP rs35771982位点的基因多态性可能与成人IMN患者治疗效果、预后相关,且rs35771982位点CC基因型可能是影响IMN患者不良预后的危险因素。     

NUDT15c.415C>T和TPMT*3C基因多态性检测方法的比较与临床应用

目的 建立准确、快速、经济的方法,检测NUDT15 c.415C>T和TPMT*3C基因多态性,探讨临床应用价值。方法 收集2017年5月-2018年5月期间福建汉族患者服用硫唑嘌呤2周以上的血清样本,提取DNA或白细胞后分别采用PCR-RFLP法、PCR-Sanger测序法和荧光定量PCR法对NUDT15 c.415C>T和TPMT*3C进行基因多态性分型,比较这3种方法的准确性、简便性及经济性。根据白细胞值分组,结合临床资料,探讨基因多态性等因素与硫唑嘌呤致白细胞减少的相关性。结果 共纳入129例患者,其中硫唑嘌呤致白细胞减少15例（11.6%）。3种方法的基因多态性检测结果一致,TPMT*3C未发现突变纯合子。携带NUDT15c.415C>T突变等位基因者服用硫唑嘌呤致白细胞减少的风险高于携带野生等位基因者（OR=6.2,95%CI：2.5~15.4,P=0.000 054）,而携带TPMT*3C突变等位基因者与野生等位基因者出现白细胞减少比例并无显著性差异（P=0.393）。NUDT15c.415C>T基因多态性预测白细胞减少敏感度为53.3%,特异度为85.1%,ROC曲线AUC为0.69。结论 3种方法都可用于临床检测NUDT15 c.415C>T和TPMT*3C基因多态性。PCR-RFLP法不需要专用试剂盒,也不需要昂贵的仪器设备,成本较低,过程简单,易于操作,特别适合条件有限的单位开展工作。福建汉族患者在服用硫唑嘌呤前进行NUDT15c.415C>T基因多态性检测比TPMT*3C更具临床价值。     

白介素1β基因多态性对质子泵抑制剂三联方案根除幽门螺杆菌疗效影响的Meta分析

目的 系统评价白介素1β（interleukin-1β,IL-1β）基因多态性与质子泵抑制剂三联方案根除幽门螺杆菌疗效的关系。方法 检索PubMed、Embase、CBM、CNKI、Wanfang data、CQVIP等数据库,收集IL-1β基因多态性（C-511T、T-31C）与质子泵抑制剂三联方案根除幽门螺杆菌感染的临床文献。根据纳入和排除标准筛选文献、评价和提取数据后,采用RevMan 5.3软件进行meta分析。结果 共纳入4篇文献,包含1 123例对象。Meta分析结果显示,IL-1β C-511T基因多态性中仅CC与TT基因型间质子泵抑制剂三联疗法的幽门螺杆菌根除率存在统计学差异（78.5%vs 92.1%,P<0.05）;CT与CC或TT基因型间幽门螺杆菌根除率无统计学差异（87.7%vs 78.5%,87.7%vs 92.1%）。IL-1β T-31C基因多态性中TT、TC与CC基因型间质子泵抑制剂三联疗法的幽门螺杆菌根除率无统计学差异（87.9%,84.6%,96.2%）。结论 IL-1β C-511T基因多态性可能影响质子泵抑制剂三联方案根除幽门螺杆菌的疗效。     

GSTP1基因多态性与结直肠癌患者奥沙利铂化疗敏感性及周围神经毒性的关系★

目的 探讨谷胱甘肽S-转移酶P1（GSTP1）基因多态性与结直肠癌患者含奥沙利铂化疗方案的敏感性及周围神经毒性（CIPN）的关系。方法 选取某医院应用奥沙利铂化疗的结直肠癌患者70例，入院后24 h内统计患者基本临床资料。所有患者于化疗前静脉采血2 mL，采用地高辛原位杂交试剂盒进行杂交染色，多通道荧光定量分析仪检测GSTP1基因型，对比不同基因型患者化疗2个周期后的疗效及毒副反应发生情况。所有患者均经mFOLFOX6/XELOX方案治疗，采用实体瘤疗效评价标准（RECIST）进行疗效评价，美国国家癌症研究所常见不良反应术语评定标准（NCI-CTCAE）进行毒副反应评估。结果 （1）患者性别、年龄、TNM分期、淋巴结转移情况、肿瘤部位、ECOG评分、化疗方案、伴发慢性病、奥沙利铂剂量等病理生理及药物因素与GSTP1基因型分布及化疗疗效无明显相关性（P>0.05）。（2） CIPN具有剂量累积性，奥沙利铂累积剂量高者CIPN发生率较高（P<0.05）。（3） GSTP1野生型与突变型患者疾病控制率分别为78.05％、89.66％，差异无统计学意义（P>0.05）。（4） GSTP1野生型患者CIPN、骨髓抑制发生率明显高于突变型患者（P<0.05），其余不良反应（乏力、胃肠道反应、口腔黏膜炎等）各基因型间的差异无统计学意义（P>0.05）。（5） 70例患者CIPN发生程度较轻，无4级以上CIPN。GSTP1基因多态性与CIPN严重程度无关（P>0.05）。结论 GSTP1基因多态性与结直肠癌患者病理生理因素、化疗疗效无关，与患者使用奥沙利铂后CIPN的发生相关。检测GSTP1基因多态性可能成为接受奥沙利铂化疗的结直肠癌患者发生CIPN的一个预测指标。     

The role of ALDH2 in tumorigenesis and tumor progression: Targeting ALDH2 as a potential cancer treatment

A major mitochondrial enzyme for protecting cells from acetaldehyde toxicity is aldehyde dehydrogenase 2 (ALDH2). The correlation between ALDH2 dysfunction and tumorigenesis/growth/metastasis has been widely reported. Either low or high ALDH2 expression contributes to tumor progression and varies among different tumor types. Furthermore, the ALDH2∗2 polymorphism (rs671) is the most common single nucleotide polymorphism (SNP) in Asia. Epidemiological studies associate ALDH2∗2 with tumorigenesis and progression. This study summarizes the essential functions and potential ALDH2 mechanisms in the occurrence, progression, and treatment of tumors in various types of cancer. Our study indicates that ALDH2 is a potential therapeutic target for cancer therapy.KEY WORDS: ALDH2, Polymorphism, Cancer, Tumorigenesis, Progression, Cancer therapy, Acetaldehyde, Metastasis     

Characteristics of aldehyde dehydrogenase 2 (Aldh2) knockout mice

Acetaldehyde is an intermediate of ethanol oxidation. It covalently binds to DNA, and is known as a carcinogen. Aldehyde dehydrogenase 2 (ALDH2) is an important enzyme that oxidizes acetaldehyde. Approximately 45% of Chinese and Japanese individuals have the inactive ALDH2 genotypes (ALDH2*2/*2 and ALDH2*1/*2), and Aldh2 knockout mice appear to be a valid animal model for humans with inactive ALDH2. This review gives an overview of published studies on Aldh2 knockout mice, which were treated with ethanol or acetaldehyde. According to these studies, it was found that Aldh2 ?/? mice (Aldh2 knockout mice) are more susceptible to ethanol and acetaldehyde-induced toxicity than Aldh2 +/+ mice (wild type mice). When mice were fed with ethanol, the mortality was increased. When they were exposed to atmospheres containing acetaldehyde, the Aldh2 ?/? mice showed more severe toxic symptoms, like weight loss and higher blood acetaldehyde levels, as compared with the Aldh2 +/+ mice. Thus, ethanol and acetaldehyde treatment affects Aldh2 knockout mice more than wild type mice. Based on these findings, it is suggested that ethanol consumption and acetaldehyde inhalation are inferred to pose a higher risk to ALDH2-inactive humans. These results also support that ALDH2-deficient humans who habitually consume alcohol have a higher rate of cancer than humans with functional ALDH2.     

Subcellular aldehyde dehydrogenase activity and acetaldehyde oxidation by isolated intact mitochondria of rat brain and liver after acetaldehyde treatment

The effect of treatment of rats with acetaldehyde on the subcellular NAD⁺-aldehyde dehydrogenase (EC 1.2.1.3, ALDH) activities and acetaldehyde oxidation by isolated intact mitochondria of the liver and the brain was studied. Inhalation of acetaldehyde caused a significant decrease in the liver mitochondrial low K_m-ALDH activity, while brain mitochondrial ALDH activity remained unchanged. Acetaldehyde oxidation by isolated intact liver mitochondria decreased significantly but that by brain mitochondria remained unchanged after acetaldehyde inhalation. These findings raise the possibility that the brain enzyme may be exposed to lower concentration of acetaldehyde than the liver enzyme.     

Alcohol and oropharyngolaryngeal and digestive tract cancer]

Epidemiology has demonstrated that alcoholic beverages are causally related to oropharyngolaryngeal, esophageal, liver, colorectal, and female breast cancer. Among Japanese male alcoholics screened by endoscopy combined with esophageal iodine staining and immunofecal occult blood tests, 4.2% had esophageal squamous cell carcinoma (SCC); 1.2%, oropharyngolaryngeal SCC; 1.4%, stomach adenocarcinoma; 1.9%, colorectal adenocarcinoma. The inactive form of aldehyde dehydrogenase-2 (ALDH2), encoded by the gene ALDH2*1/2*2, which is prevalent in Asians, exposes them to higher levels of acetaldehyde after drinking and was a strong risk factor for these cancers among Japanese heavy drinkers. Inactive ALDH2 was also associated with synchronous and metachronous multiple esophageal cancers. These results suggest a general role of acetaldehyde, an established animal carcinogen, in carcinogenesis of the human alimentary tract. The oropharyngolarynx and esophagus lack ALDH2 activity, suggesting that after exposure to acetaldehyde derived from systemic, mucosal, salivary, or bacterial production or alcoholic beverages, these organs' inefficient degradation of acetaldehyde enhances the chances for local acetaldehyde-associated carcinogenesis. The normal alcohol dehydrogenase-2 (ADH2), encoded by ADH2*1/2*1, is another risk factor for oropharyngolaryngeal and esophageal cancer in Japanese alcoholics. For patients with both normal ADH2 and inactive ALDH2, the risks for oropharyngolaryngeal and esophageal cancer are enhanced in a multiplicative fashion. The responses to a simple questionnaire about both current and past facial flushing after drinking a glass of beer can indicate an individual's ALDH2 phenotype fairly well. Use of this questionnaire to obtain information on ALDH2-associated cancer susceptibility could contribute to the prevention of alcohol-related cancer in Asians.     

Involvement of acetaldehyde for full protection against alcoholism by homozygosity of the variant allele of mitochondrial aldehyde dehydrogenase gene in Asians

There is a functional polymorphism of the mitochondrial aldehyde dehydrogenase (ALDH2) gene with the variant allele (ALDH2*2) encoding a protein subunit that confers low activity to the tetrameric enzyme. Genetic epidemiologic studies have strongly suggested that homozygosity for the allele ALDH2*2 is sufficient in completely inhibiting the development of alcoholism in Asians. To study the pathophysiology of this unique pharmacogenetic effect, we recruited a total of eighteen adult Han Chinese men, matched by age, body-mass index, nutritional state and homozygosity at the alcohol dehydrogenase gene loci from a population base of 273 men. Six individuals were chosen for each of the three ALDH2 allelotypes: homozygous ALDH2*2/*2, heterozygous ALDH2*1/*2, and homozygous ALDH2*1/*1. Following a low dose of ethanol (0.2 g/kg body weight), blood ethanol/acetaldehyde concentrations, cardiac and extracranial/intracranial arterial hemodynamic parameters, as well as self-rated subjective sensations, were measured for 130 min. Homozygous ALDH2*2 individuals were found to be strikingly responsive to the small amount of alcohol, as evidenced by the pronounced cardiovascular hemodynamic effects as well as subjective perception of general discomfort for as long as 2 h following ingestion. This low-dose alcohol hypersensitivity, accompanied by a prolonged and large accumulation of acetaldehyde in blood, provides an explanation for the strong protection against heavy drinking and alcoholism in individuals homozygous for the ALDH2*2 gene allele.     

Ontogeny of the activity of alcohol dehydrogenase and aldehyde dehydrogenases in the liver and placenta of the guinea pig

The objectives of this study were to elucidate the ontogeny of the activity of alcohol dehydrogenase (ADH), low Km aldehyde dehydrogenase (ALDH) and high Km ALDH in the liver and placenta of the guinea pig, and to determine the relationship between the relative activity of each enzyme in the guinea pig maternal-placental-fetal unit and the disposition of ethanol and its proximate metabolite, acetaldehyde. The enzyme activities were determined in maternal liver, fetal liver, and placenta of the guinea pig at 34, 50, 60 and 65 days of gestation (term, about 66 days), in the liver of the 2-day-old neonate, and in adult liver. There was low ADH activity in fetal liver and placenta throughout gestation and in neonatal liver. The fetal liver low Km ALDH activity increased progressively and, at 60 days of gestation, was similar to adult liver activity, as was also the case for neonatal liver enzyme activity. Placental low Km ALDH activity was less than adult liver activity throughout gestation. Fetal hepatic high Km ALDH activity increased during gestation, but was less than adult liver activity, as was also the case for neonatal liver enzyme activity. Placental high Km ALDH activity was low throughout gestation. For oral administration of 0.5 g ethanol/kg maternal body weight to pregnant guinea pigs at mid-gestation (34 days), the maternal blood and fetal body ethanol concentration-time curves were similar. Acetaldehyde was measurable in maternal blood and fetal body at similar concentrations, which were 100- to 1000-fold less than the respective ethanol concentrations. The major difference in the disposition of ethanol and acetaldehyde at near-term pregnancy, compared with mid-gestation, was the lack of measurable acetaldehyde in fetal blood. These results indicate that the guinea pig fetus throughout gestation has virtually no capacity to oxidize ethanol, and its duration of exposure to ethanol is regulated by maternal hepatic ADH-catalyzed biotransformation of ethanol. The fetus, however, appears to have increasing low Km ALDH-dependent capacity to oxidize ethanol-derived acetaldehyde during development, and would appear to be increasingly protected from exposure to acetaldehyde as gestation progresses.     

THE EFFECTS OF THE ALDH2*1/2, CYP2E1 C1/C2 AND C/D GENOTYPES ON BLOOD ETHANOL ELIMINATION

The effects of CYP2E1 genotypes on the blood ethanol and acetaldehyde levels were investigated in a pair of Japanese volunteers whose ADH2, ADH3 and ALDH2 genotypes were identical but whose CYP2E1 genotypes were different. In the same way, the effects of ALDH2 and ADH2 on the ethanol elimination kinetics were also studied.

The predicting 95% confidence bounds determined on regression analysis of the data suggested that after venous injection of ethanol, the blood ethanol and acetaldehyde concentrations in a volunteer normal homozygous for ALDH2 (ALDH2*1/1) were lower than in a heterozygous one (ALDH2*1/2). Also, the blood ethanol and acetaldehyde concentrations in a volunteer with the c2 and C alleles of CYP2E1 (c1/c2 and C/D) were lower than in one without the c2 and C alleles (c1/c1 and D/D). However, there were no significant differences in the blood ethanol and acetaldehyde concentrations between volunteers with ADH2*1 (ADH2*1/1) and without ADH2*1 (ADH2*1/2).

It is possible that the ALDH2*1, and c2 and/or C alleles may correspond to the higher blood ethanol and acetaldehyde elimination rates after the intravenous administration of 0.2 g/kg of ethanol.     

Molecular genetics of human aldehyde dehydrogenase.

Four non-allelic genes, which encode four different aldehyde dehydrogenase (ALDH) isozymes, have been cloned and characterized at the present time. The coding nucleotide sequences, and organization of introns and exons of these genes have been elucidated. The ALDH1 gene encodes the major cytosolic ALDH1 existing in the liver and other tissues. The genetic deficiency of this isozyme was found at a low frequency (< 10%) in both Caucasians and Orientals. The deficiency and alcohol sensitivity character are inherited together in one large Caucasian family examined. The ALDH1 gene contains two hormone response elements in its upstream 5' region. The ALDH2 gene encodes the major liver mitochondrial ALDH2 which has a very low Km for acetaldehyde. The atypical ALDH2(2) allele is common (about 30%) in Orientals; and subjects with ALDH2(2) allele, both homozygous and heterozygous status, lack ALDH activity. These individuals are alcohol sensitive and have a markedly reduced risk in developing alcoholism and alcoholic liver diseases. The ALDH3 gene produces a cytosolic ALDH3 isozyme existing in the stomach and liver carcinoma but hardly in normal liver. The ALDH3 locus is polymorphic in Orientals and presumably other populations. The ALDH5 gene, which is expressed in testes and liver, is highly polymorphic in both Caucasians and Orientals. The variation of these two loci may affect the development of alcohol-related problems.     

A Comparative Study on the Effects of Disulfiram,Cyanamide and 1-Aminocyclopropanol on the Acetaldehyde Metabolism in Rats

Abstract 1-aminocyclopropanol (ACP) is a potent inhibitor of aldehyde dehydrogenase (ALDH) in vivo and in vitro. Like cyanamide it has a rapid onset of action in vivo with the highest inhibition occurring after 2-24 hrs. and a long duration of action like disulfiram with measurable inhibition after 144 hrs. All the three inhibitors decreased the activity of the mitochondrial low-K_m ALDH strongly in vivo, however, in markedly different doses. Cyanamide inhibited the high-K_m ALDH only in vivo, whereas in vitro, the high-K_m ALDH was unaffected by cyanamide but significantly inhibited by disulfiram and ACP. The inhibition produced by the inhibitors appeared to be irreversible. Acetaldehyde protected the low-K_m enzyme at different extents depending on the inhibitor used. The inhibition of ALDH in intoxicated and control rats and its relation to acetaldehyde oxidation and the disulfiram-ethanol reaction are discussed.     

丁香酚与甲基丁香酚的抗焦虑作用机制研究

目的 探究丁香酚及甲基丁香酚的抗焦虑作用及机制。方法 90只雄性SPF级SD大鼠,随机分为对照组,模型组,地西泮（1 mg/kg）组,丁香酚低、中、高剂量（10、20、40 mg/kg）组和甲基丁香酚低、中、高剂量（10、20、40 mg/kg）组,每组10只,对照组和模型组给予0.5% CMC-Na溶液,每只大鼠给药1 mL,ig给药,给药7 d后,除对照组外,进行高架十字迷宫实验。采用酶联免疫法（ELISA）测定焦虑大鼠血清中沉默信息调节因子2相关酶1（SIRT1）、单胺氧化酶A（MAO-A）、儿茶酚-O-甲基转移酶（COMT）、乙醛脱氢酶（ALDH）及醛糖还原酶（AR）的表达量,同时通过逆转录-聚合酶链反应（RT-PCR）检测各组海马体组织中相应的基因表达水平。结果 丁香酚高剂量组大鼠进入开放臂次数（OE）百分比和开放臂停留时间（OT）百分比显著高于模型组（P<0.01）,作用呈剂量相关性;随着剂量的增加,甲基丁香酚表现出抗焦虑作用趋势,但差异无统计学意义。与对照组比较,模型组大鼠SIRT1和MAO-A酶含量及基因表达显著升高（P<0.05、0.01）,丁香酚与甲基丁香酚均发挥显著回调作用（P<0.01）。与对照组比较,模型组大鼠血清中ALDH与AR含量显著下降,COMT含量显著升高（P<0.01）;海马组织中COMT与ALDH的基因表达显著上调,AR的基因表达显著下调（P<0.01）。与模型组比较,丁香酚可显著回调血清COMT、ALDH及AR含量（P<0.05、0.01）,甲基丁香酚显著回调血清COMT、AR含量（P<0.05、0.01）;丁香酚与甲基丁香酚能够显著抑制焦虑大鼠海马体COMT与ALDH的基因表达上调（P<0.01）,甲基丁香酚显著抑制AR的基因表达下调（P<0.05）。结论 丁香酚和甲基丁香酚抗焦虑活性良好,可通过调控SIRT1-MAO-A信号通路进而影响单胺类神经递质5-羟色胺（5-HT）的代谢以及儿茶酚胺代谢通路中COMT、ALDH及AR酶的活性和基因表达发挥作用。