AT1基因启动子区单核苷酸多态与原发性高血压合并冠心病相关

目的：在中国华东地区汉族人群中检测Ⅰ型血管紧张素Ⅱ受体(AT1)基因启动子区单核苷酸多态(SNPs)的分布，并研究其与原发性高血压合并冠心病的关系：方法：运用PCR直接测序法检测AT1基因启动子区．并对160例原发性高血压、151例冠心病、185例原发性高血压合并冠心病及160名健康对照进行基因分型。结果：在AT1基因启动子区共发现6个SNPs．属同一单倍域．其中-810T／A多态与另4个SNPs(-713G／T．-214A／C、-213G／C和-153A／G)几乎呈完全的连锁不平衡：-810T／A多态的基因型和等位基因分布在原发性高血压组与对照组间无统计学差异。冠心病组与对照组相比，-810T／A多态的基因型(x^2=3．588，P=0．058)和等位基因(x^2=3．769．P=0．052)分布均达到统计学临界值、-810T／A多态的基因型分布在原发性高血压合并冠心病组(TT=126．TA AA=59）分别与原发性高血压组(TT=127．TA AA=33，x^2=5．569，P=0．018)和对照组（TT=130，TA AA=30，x^2=7．741．P=0．005)相比，差异均有显性。原发性高血压合并冠心病组的A等位基因频率显高于对照组(0.181比0．106．x^2=7，690．P=0.006)和原发性高血压组(0．181比0．125，x^2=4．119，P=0．042)结论：AT1基因-810T／A多态可能是中国华东地区汉族人群原发性高血压合并冠心病的遗传危险因素。     

血管紧张素原基因核心启动子区A-6G多态性与白族原发性高血压的关联分析

目的:研究血管紧张素(angiotensinogen,AGT)基因核心启动子区A-6G多态性与白族人原发性高血压之间的关联.方法:以67例白族原发性高血压患者(高血压组)和54例健康体检者(对照组)为研究对象进行病例对照研究.用聚合酶链反应.限制性片段长度多态性方法分析AGT基因(-6)位点多态性;用自动荧光测序方法,对AGT基因核心启动子区DNA序列进行突变分析及验证基因分型.结果:(1)白族AGT基因核心启动子区域(-6)位点存在A→G突变.(2)AGT基因(-6)位点AA、AG、GG基因型频率及A、G等住基因频率在高血压组和对照组之间无统计学差异(P>0.05).(3)AGT基因(-6)住点各基因型收缩压和舒张压水平无统计学差异(P>0.05).结论:AGT基因A-6G多态性可能与白族人原发性高血压的发生无关.     

成都汉族群体MMPs和TIMPs基因单核苷酸多态性及单体型分析

目的研究MMPs和TIMPs基因单核苷酸多态性(SNPs)在中国成都汉族人群中的分布特点。方法采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法检测132名中国成都汉族个体MMPs基因6个SNPs(MMP1-1607 1G/2G、MMP2-1306C/T、MMP2-735C/T、MMP3-1612 5A/6A、MMP9-1562C/T、MMP21 572C/T)和TIMPs基因2个SNPs(TIMP2 303C/T、TIMP3-1296C/T)的多态性,并与中国北方汉族及日本、欧洲群体的MMPs和TIMPs基因SNPs等位基因频率的分布进行比较。结果获得了成都汉族人群的MMPs和TIMPs基因8个SNPs的群体遗传学资料。除MMP21 572C/T位点外,其余MMPs和TIMPs的SNPs基因型及等位基因频率及单体型的频率分布与中国北方汉族人群、日本及欧洲等人群之间的比较具有统计学意义(P<0.05)。结论成都地区汉族人群MMPs和TIMPs基因8个SNPs的等位基因频率同其他地区人群的存在较明显的不同。     

宁夏汉族人群eNOS基因3个SNP位点与原发性高血压相关性的研究

目的:探讨在宁夏地区汉族人群中eNOS基因3个SNP位点与原发性高血压(EH)的相关性.方法:采用PCR-RFLP方法对204例EH患者及219例健康个体eNOS基因rs2070744(T＞ C)、rs1800780(A＞G)和rs3918181 (A＞ G)共3个SNP位点检测.用x2检验比较病例组-对照组间基因型频率、等位基因频率的差异,用SHEsis在线分析软件分析单倍型 结果:EH组和对照组间,rs1800780位点基因型频率的分布存在显著性差异(P＜ 0.05).rs2070744位点及rs3918181位点基因型频率及等位基因频率的分布均无显著性差异(P＞ 0.05).3个SNP位点共检出8种单倍型,其中单倍型TGA在对照组及EH患者中有统计学差异(P＜0.05),且OR (95％ CI)为1.549 (1.116 ～ 2.150).结论:单倍型TGA的出现可能会增加汉族EH的患病风险.     

TBX-21基因启动子区单倍型与食管鳞癌易感风险的关联研究

目的探讨中国汉族人群中,肿瘤免疫调节基因TBX-21启动子区单倍型与食管鳞癌的遗传易感风险的关联性。方法提取257例食管鳞癌患者及281例健康者外周血基因组DNA,根据前期研究中用PCR-RFLP的方法检测得到的两组人群中TBX-21基因启动子区-1499(G/A)、-1514(T/C)两个多态性位点的基因型;采用PHASE2.0软件构建这两个多态性位点的单倍体型,以非条件Logistic回归校正混杂因素,并进行多态性与食管鳞癌患者易感关联及临床病理特征相关性的统计学分析。结果 TBX-21基因启动子区-1499(G/A)、-1514(T/C)两个多态性位点的单倍型在中国汉族人群中共有4种,分别为G-T、G-C、A-T、A-C。通过校正性别与年龄、吸烟与饮酒、肿瘤家族史等因素后,Logistic回归分析显示在这两个位点所构建的单倍体型中,病例组含有A-T单倍体的个体与对照组相比具有显著性差异:OR=1.56,95%CI=1.01～2.41,P=0.044;含有A-C单倍体的个体在两组人群中的差异性更为显著:OR=7.04,95%CI=2.05～24.39,P=0.002。但这两个位点构成的4种单倍体型与肿瘤的大小、分化、TNM分期、淋巴结转移及远处转移均无相关性(P>0.05)。结论 TBX-21基因启动子区-1499(G/A)、-1514(T/C)多态性位点构成的单倍体型中,具有A-T、A-C单倍体的个体食管鳞癌的患病风险分别增加1.56倍和7.04倍,但与食管鳞癌的临床病理学特征无相关性。     

中国汉族人群ABCB1基因SNPs与单倍型频率分析

目的:分析中国汉族人群中ABCB1基因SNPs频率与单倍型频率。方法:采用DNA直接测序法对130例汉族人ABCB1基因-129T>C,1236C>T,2677G>T/A和3435C>T测序并构建单倍型,分析各个SNPs频率与单倍型频率。结果:突变位点-129C、1236T、2677T、2677A和3435T频率分别为4.62%、64.23%、35.00%、12.69%和35.38%;单倍型T-T-T-T和C-T-T-T频率分别为31.15%和0.77%。结论:汉族人群中ABCB1基因功能性的SNP突变位点与单倍型频率较高,对相关SNPs和单倍型进行基因分型可以指导临床上P-糖蛋白相关药物的安全有效使用。     

醛糖还原酶和内皮型一氧化氮合酶基因多态性并存与糖尿病肾病发病的相关性(英文)

背景:有关资料显示,醛糖还原酶基因启动子区C-106T多态和内皮型一氧化氮合酶基因第七外显子GLU298ASP(894G→T)多态与糖尿病肾病有关,上述基因多态并存时,2型糖尿病患者糖尿病肾病的发病风险是否明显增加有待进一步研究。目的:探讨染色体7q35区醛糖还原酶基因启动子区C-106T多态和内皮型一氧化氮合酶基因第七外显子GLU298ASP(894G→T)多态并存时与中国北方汉族人群糖尿病肾病发病的关系。设计:病例-对照,对比观察。单位:青岛大学医学院附属医院内分泌科。对象:选择2002-11/2005-04在青岛大学医学院附属医院内分泌科住院2型糖尿病患者139例,男54例,女85例,年龄(64±8)岁。符合1999年世界卫生组织关于糖尿病诊断和分类标准。根据24h尿微量白蛋白排泄率分为2组:糖尿病肾病组61例和非糖尿病肾病组78例。选择同期本院体检健康成人63名为对照组,男24名,女39名;年龄50～78岁。纳入对象均为汉族,且对检测项目知情同意。方法:运用聚合酶链反应限制性片段长度多态性技术、DNA测序技术及琼脂糖凝胶电泳分离技术检测纳入对象的醛糖还原酶基因启动子区C-106T多态位点和内皮型一氧化氮合酶基因第7外显子GLU298ASP(894G→T)多态位点的等位基因和基因型。主要观察指标:①醛糖还原酶和内皮型一氧化氮合酶基因多态性。②糖尿病肾病危险因素的多元逐步回归分析结果。③醛糖还原酶C-106T多态和内皮型一氧化氮合酶894G→T多态与糖尿病肾病相对危险度。结果:2型糖尿病患者139例和健康人63名全部进入结果分析。①糖尿病肾病组内皮型一氧化氮合酶基因第7外显子894G→T多态位点的T等位基因和TG基因型频率明显高于非糖尿病肾病组和对照组(χ2=8.261,19.629,P<0.01)。②糖尿病肾病组醛糖还原酶基因启动子区C-106T多态位点的T等位基因和CT基因型频率明显高于非糖尿病肾病组和对照组(χ2=6.343,8.940,P<0.05,0.01)。③将上述基因多态联合分析发现,糖尿病肾病组的TG/CT基因型频率明显高于非糖尿病肾病组和对照组(χ2=6.972,P<0.01);GG/CC基因型频率显著低于非糖尿病肾病组和对照组(χ2=13.304,P<0.01)。④糖基化血红蛋白、收缩压、总胆固醇、内皮型一氧化氮合酶基因的第七外显子894G→T多态及醛糖还原酶基因启动子区C-106T多态均是糖尿病肾病的独立危险因素(Wald=5.627,4.92,P<0.05)。⑤GG/CC基因型可能是糖尿病肾病的保护基因型(OR=0.25,P<0.01);GG/CT或TG/CC基因型携带者糖尿病肾病的危险性增加2.3倍,TG/CT基因型携带者糖尿病肾病的危险性增加4.8倍。结论:内皮型一氧化氮合酶基因第7外显子894G→T多态位点的T等位基因和TG基因型和醛糖还原酶基因启动子区C-106T多态位点的T等位基因和CT基因型增加2型糖尿病患者发生糖尿病肾病的危险性,两种基因多态并存时,糖尿病肾病的发病风险明显增加。     

中国汉族人群UGT1A1基因非翻译区序列分析

目的:对中国汉族人群尿苷二磷酸葡糖醛酸基转移酶1A1(uridine diphosphate glucuronosyltransferase 1A1,UGT1A1)基因的5'和3'-非翻译区序列进行分析,寻找非翻译区的多态性变异。方法:收集220例健康汉族个体的外周血,并抽提基因组DNA,通过聚合酶链反应扩增UGT1A1基因的5'和3'-非翻译区,通过测序确定DNA序列。结果:在中国汉族人群中UGT1A1基因的5'非翻译区存在2个多态性位点:-64(G/C)和TATAA盒区A(TA)6TAA/A(TA)7TAA;-64位G频率为98.4%,C频率为1.6%。TATAA盒中A(TA)6TAA频率为93.4%,A(TA)7TAA频率为6.6%。3'非翻译区也存在2个多态性位点:1813C/T和1941C/G,所有个体在1813和1941位点均呈纯合性,且1813C和1941C呈遗传共分离(单倍型频率为73.6%),1813T和1941G(单倍型频率为26.4%)呈遗传共分离。结论:中国汉族人群UG T1A1基因的3'-非翻译区1813和1941纯合多态性位点呈遗传共分离可能是基因组自然选择的结果,其机制有待进一步研究。     

血管紧张素原基因部分多态性指标与原发性高血压的发病风险:社区病例对照

背景:血管紧张素原基因是第一个被发现的原发性高血压候选基因,T174M5和M235T多态均位于AGT基因第二外显子,且存在连锁不平衡。启动子区域A-6G和G-217A位点多态对其基因表达起重要调节作用,且血管紧张素原基因的表达产物与血压水平的维持密切相关。目的:探讨血管紧张素原基因A-6G,T174M和G-217A位点多态性与中国汉族人群原发性高血压发病风险的关系。设计:整群抽样,病例-对照分析。单位:南京医科大学第一附属医院老年医学科与心血管科,国家人类基因组南方研究中心,江苏省东台市人民医院心血管科。对象:实验于2005-09/10在江苏省东台市农村完成。①263例实验对象均来自江苏省盐城市东台县农村,其中原发性高血压组177例为未经药物治疗的原发性高血压患者,高血压的诊断参照1999年WHO/ISH高血压诊断标准(收缩压≥140mmHg和/或舒张压≥90mmHg);正常对照组86例。②纳入标准:实验对象为汉族;长期居住本地非外来人口;能清楚回答问题;经病史、临床症状、体征及辅助检查确诊;统一问卷面访调查资料完整。③排除标准:原发性高血压组排除继发性高血压,正常对照组排除高血压家族史,同时两组人群均排除肝、肾慢性疾病和糖尿病。方法:采集外周静脉血3mL,用FlexiGeneDNAKit(250)提取人外周血中DNA。应用primer3软件进行引物设计,并排除引物序列中的多态位点。多重聚合酶链反应扩增后,取3μL反应产物用琼脂糖凝胶电泳检测扩增结果,扩增成功的聚合酶链反应产物用QIAquickPCRPurifica-tionKit纯化,纯化后的产物用DNaseⅠ片段化,片段化的酶切产物以脱氧核苷酸末端转移酶进行荧光素标记。每个单核苷酸多态各设计2条等位基因特异性探针和1条错配探针,芯片用OmniGridTM100点样仪制备,每个探针重复3次,形成3个阵列。杂交液95℃变性10min后,立即置于冰上冷切,取10μL杂交液加入到芯片矩阵上,50℃杂交2h,然后洗涤,甩干。GenePix4000B共聚焦激光扫描仪进行芯片扫描,利用GenePixPro提取得到每条探针的荧光信号强度值,通过计算每个单核苷酸多态的等位基因分数判断基因型。主要观察指标:①两组血管紧张素原基因各多态位点基因型分布频率的比较。②血管紧张素原基因A-6G和T174M位点多态性与原发性高血压发病风险的相关分析。③两组血管紧张素原基因A-6G,T174M和G-217A位点多态性对血压的影响。结果:按意向处理分析,263例实验对象均进入结果分析。①血管紧张素原基因A-6G位点AA,AG,GG基因型(P=0.014)以及A,G等位基因频率(P=0.004,OR=0.44)差异明显;T174M位点CC,CT,TT基因型(P=0.031)以及C,T等位基因频率(P=0.014,OR=0.55)差异有显著性意义;未发现G-217A位点GG,AG,AA基因型(P=0.722)以及G,A等位基因频率(P=0.403,OR=0.80)有明显差异。②携带A-6G多态AA基因型和T174M多态CC基因型的个体发生原发性高血压的风险分别减少57%(95%可信区间=0.23～0.82,P=0.010)和56%(95%可信区间=0.25～0.79,P=0.006)。③两组血管紧张素原基因A-6G,T174M和G-217A位点各基因型的收缩压、舒张压和平均动脉压的差异均无显著性意义(F=0.100～2.911,P均>0.05)。结论:血管紧张素原基因A-6G位点AA基因型和T174M位点CC基因型可能会减少中国汉族人群原发性高血压发病风险,未发现G-217A多态基因型与其有显著相关性。     

中国汉族健康群体多巴胺D1受体-48A/G基因多态性分布

目的:了解中国汉族健康群体多巴胺D1受体-48A/G基因的多态性。方法:随机收集2004-03/07武汉大学人民医院门诊体检中心健康汉族人188名,其中男112名,女76名。用聚合酶链反应-限制性片段长度多态性方法,分析限制性酶切位点-48A/G的多态分布。结果:188名健康人的测试结果进入分析。①多巴胺D1受体-48A/G基因型在中国汉族健康人群中的分布特点:以AA纯合子型最多见(0.71),AG杂合子型次之(0.28),GG纯合子型最为罕见(0.01);等位基因频率的分布以A等位基因最多见(0.85),其次为G等位基因(0.15)。在男女性别之间,基因型频率(χ2=1.582,P>0.05)和等位基因频率(χ2=0.606,P>0.05)分布差异无显著性。②不同种族间多巴胺D1受体-48A/G基因型分布的比较:中国汉族健康群体多巴胺D1受体-48A/G等位基因的分布与高加索、德国及日本人群相比差异有显著性(P<0.01);在基因型的分布上,与日本人群也存在显著性差异(P<0.01)。结论:中国汉族健康群体多巴胺D1受体-48A/G以AA纯合子基因型最多,等位基因频率的分布以A等位基因最多;在男女性间的基因型频率和等位基因频率分布无差异。中国汉族健康群体与高加索、德国及日本报道的人群多巴胺D1受体-48A/G等位基因分布和基因型的分布不同。     

Cosegregation of the renin allele of the spontaneously hypertensive rat with an increase in blood pressure.

The spontaneously hypertensive rat (SHR) exhibits alterations in the renin-angiotensin-aldosterone system which are similar to those that characterize patients with "nonmodulating" hypertension, a common and highly heritable form of essential hypertension. Accordingly, we determined whether the inheritance of a DNA restriction fragment length polymorphism (RFLP) marking the renin gene of the SHR was associated with greater blood pressure than inheritance of a RFLP marking the renin gene of a normotensive control rat. In an F2 population derived from inbred SHR and inbred normotensive Lewis rats, we found the blood pressure in rats that inherited a single SHR renin allele to be significantly greater than that in rats that inherited only the Lewis renin allele. To the extent that the SHR provides a suitable model of "nonmodulating" hypertension, these findings raise the possibility that a structural alteration in the renin gene, or a closely linked gene, may be a pathogenetic determinant of increased blood pressure in one of the most common forms of essential hypertension in humans.     

Renal nerves modulate renin gene expression in the developing rat kidney with ureteral obstruction.

Chronic unilateral ureteral obstruction (UUO) in newborn rats activates renin gene expression in the obstructed kidney, and increases renin distribution along afferent glomerular arterioles in both kidneys. To investigate the role of the renal nerves in this response, 2-d-old Sprague-Dawley rats were subjected to UUO or sham operation. Chemical sympathectomy was performed by injection of guanethidine, whereas, control groups received saline vehicle. At 4-5 wk, renal renin distribution was determined by immunocytochemistry, and renin mRNA levels were determined by Northern blot hybridization. Compared to the saline-treated rats with UUO, renin remained localized to the juxtaglomerular region in both kidneys of rats with UUO receiving guanethidine (P less than 0.05). Moreover, renin mRNA levels were eightfold lower in obstructed kidneys of rats receiving guanethidine than in those receiving saline. Additional groups of rats with UUO were subjected to unilateral mechanical renal denervation: renin gene expression in the obstructed kidney was suppressed by ipsilateral but not by contralateral renal denervation. These findings indicate that either chemical or mechanical denervation suppressed the increase in renin gene expression of the neonatal kidney with ipsilateral UUO. We conclude that the renal sympathetic nerves modulate renin gene expression in the developing kidney with chronic UUO.     

Diuretic therapies in low renin and normal renin essential hypertension.

This study was designed to compare the effectiveness of spironolactone, hydrochlorothiazide, and combined spironolactone-hydrochlorothiazide therapy in patients with low renin and those with normal renin essential hypertension. Patients with low renin hypertension had a greater hypotensive response to each regimen (p less than 0.001). Low renin patients responded equally to both spironolactone and to hydrochlorothiazide, and in low renin but not in normal renin patients reduction of blood pressure correlated with weight loss. These results suggest that a volume factor, not specifically related to increased mineralocorticoid production, contributes to the pathogenesis of low renin essential hypertension.     

Study of V1a vasopressin receptor gene single nucleotide polymorphisms in platelet vasopressin responsiveness

There is a significant heterogeneity among individuals in terms of platelet aggregation response to arginine vasopressin (AVP). The aim of this study was to evaluate whether four single nucleotide polymorphisms (SNPs) in the promoter region of vasopressin V1a receptor gene (V1aR) could be used as genetic markers for divergent platelet aggregation response to AVP. Seventeen of 33 subjects showed more than 60% of maximum platelet aggregation and were classified as responders. Sixteen were classified as nonresponders because they had less than 30% aggregation. In a preliminary study, V1aR gene sequences were determined in two responders and two nonresponders. We found four SNPs in the promoter region of the V1aR gene: -6951G/A, -4112A/T, -3860T/C, and -242C/T. In all 33 subjects the genotypes of four SNPs were determined using either polymerase chain reaction (PCR) with allele-specific primers or PCR followed by restriction-fragment length polymorphism (RFLP). There were no differences in the AVP-induced aggregation between the subjects with and without variant alleles of each four SNPs. The genotype frequencies of four SNPs of V1aR were almost identical between AVP responders and nonresponders. These results suggest that the four SNPs in the promoter region of the V1aR gene may not be useful as genetic markers for platelet aggregation heterogeneity.     

Effect of intravenous frusemide on plasma renin concentration: suppression of response in hypertension.

1. Intravenous frusemide produced in normal subjects a prompt rise of plasma renin concentration which correlated with urinary sodium. 2. The renin response to frusemide was suppressed in patients with primary hyperaldosteronism. 3. In patients with low-renin hypertension and normal renin essential hypertension, the renin response to frusemide was similarly suppressed. 4. Suppression of the renin response to frusemide is therefore a feature of hypertension not confined to patients with primary hyperaldosteronism and low-renin hypertension. 5. Thus low-renin hypertension does not appear to constitute a distinct diagnostic entity. 6. It is suggested that suppression of the renin response is part of a long-term renal adaptation to high blood pressure.     

内脏素启动子区-3186C〉T的单核苷酸多态性：非酒精性脂肪肝与正常人群的比较

目的：采用酶连接检测反应和基因芯片相结合的检测方法，检测东北地区汉族人群内脏素基因启动子区-3186C〉T的单核苷酸多态性（SNPs-3186C〉T），并分析其与非酒精性脂肪肝的相关性。 方法：选择2006—01／2007—05于吉林大学第一医院诊断明确的非酒精性脂肪肝患者79例，以及同期的健康体检者69例，运用酶连接检测反应和基因芯片相结合的方法，检测所有受试者的内脏素基因启动子区-3186C〉T的单核苷酸多态性，同时测量受试者的身高、体质量、腰围、臀围，并检测空腹胰岛素水平、肝功能、血糖、血脂等临床指标。所有受试者均为东北地区的汉族人，均签署了知情同意书。 结果：①CC，CT，TT基因型在非酒精性脂肪肝患者中分别为22．78％，50．63％，26．58％，在正常对照组中分别为21．74％，53．62％，24．64％。SNPs-3186C〉T的基因型频率和等位基因频率在两组中的分布差异无显著性（P〉0．05）。②非酒精性脂肪肝患者的SNPs-3186C〉T不同基因型的各测量指标及临床指标比较差异均无显著性（P〉0．05）。 结论：在东北地区汉族人中存在内脏素基因启动子区-3186C〉T的单核苷酸多态性，但与非酒精性脂肪肝无相关性。     

Activity of Erythropoietin and Renin in Renal Venous Blood of Hypertensive Patients

Plasma activities of renin and erythropoietin were determined in the renal veins of the right and left kidneys of hypertensive patients. The patients were divided into the following groups either according to the origin of the hypertension (group 1: control or essential hypertension, group 2: renovascular hypertension) or according to the hormone levels (group 3: renin activity exceeding 10 ng/litre in at least one of the renal veins and group 4: erythropoietin activity higher than 4% 5 9Fe incorporation in at least one of the renal veins). In groups 1, 2 and 3 a statistically significant difference in renin activity was found between the kidney with the higher renin activity and that with the lower activity However, in group 4, the side, which showed elevated erythropoietin values also had higher renin activity as compared to the essential hypertensive group. Erythropoietin activity probably does not parallel the increased renin activity found in renovascular hypertension or in some cases of non-renovascular hypertension. However, in several cases of renal vascular alterations, both systems can be activated simultaneously.     

Angiotensinogen gene and hypertension in Chinese.

The renin-angiotensin system plays a major role in regulating blood pressure and maintaining electrolyte and volume homeostasis. Previously, the angiotensinogen gene, which encodes the key substrate for renin within this system, has been reported linked to and associated with essential hypertension in White Europeans, African-Caribbeans, and Japanese. Therefore, we investigated whether the angiotensinogen gene might be similarly implicated in the pathogenesis of essential hypertension in Chinese by carrying out linkage analysis in 310 hypertensive sibling pairs. Genotypes for two diallelic DNA polymorphisms observed at amino acid residues 174 (T174M) and 235 (M235T) within the coding sequence and for two highly informative dinucleotide (GT)-repeat sequences (one in the 3' flanking region, and one at a distance of 6.1 cM from the gene) were determined. Affected sibpair analysis conducted according to three different algorithms (S.A.G.E./SIBPAL, MAPMAKER/ SIBS, and APM methods) revealed no evidence for linkage of the angiotensinogen gene to hypertension. Our data indicate that molecular variants of this gene do not appear to contribute materially to the pathogenesis of primary hypertension among Chinese (a notion supported by concomitant, direct estimates of power), and that the disease relevance of this gene may vary therefore depending on ethnicity.     

A new sensitive direct radioimmunoassay for human plasma renin and its clinical application

We developed new sensitive direct radioimmunoassay for human plasma renin. Renin was purified from Haas' preparation utilizing a pepstatin-C6-Sepharose affinity chromatography. Antiserum, prepared by immunizing rabbits with the purified renin, was used for the direct radioimmunoassay at a final dilution of 1:30,000. The antibody was specific for human renal and plasma renin, but did not cross-react with cathepsin D, trypsin, or renins of mouse, dog, and rat. Radioimmunoassay was performed by the double antibody technique using the delayed tracer addition method. In this method, a standard curve was obtained over a range from 0.2 to 8.0 ng/ml. The values from our assay correlated well with total renin activity measured as the generation rate of angiotensin I after trypsin activation (r = 0.78, p less than 0.01), but correlated weakly with active renin activity. This finding disclosed that both active and inactive renin were detected by this method. In normal participants, plasma renin concentration determined by direct radioimmunoassay was increased by standing and furosemide injection. The plasma renin concentration determined by direct radioimmunoassay of patients with essential hypertension (0.7 to 1.7 ng/ml) was not significantly different from values in normal controls (0.8 to 1.9 ng/ml). The values were higher in patients with renovascular hypertension (1.6 to 2.7 ng/ml), malignant hypertension (2.8 to 3.4 ng/ml) and Bartter's syndrome (1.8 to 2.5 ng/ml), but lower in patients with primary aldosteronism (0.4 to 0.8 ng/ml) than in normal controls. This newly developed radioimmunoassay for human renin was sensitive enough to estimate the levels of renin in plasma of patients with low renin hypertension. It provides a new tool for the understanding of the renin-angiotensin system under various clinical conditions.