Morgan K, Wharton J, Webb J C, Keogh B E, Smith P L, Taylor K M, Oakley C M, Polak J M, Cleland J G
Department of Clinical Cardiology, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.
J Hypertens Suppl. 1994 Jul;12(4):S11-9.
To detect co-expression of genes coding for components of the renin-angiotensin system and investigate the potential for variation in the level of angiotensin converting enzyme (ACE) gene expression in the right atrial appendage of patients undergoing heart surgery.
The right atrial appendage was collected at the time of surgery from 30 randomly chosen patients and was rapidly frozen in liquid nitrogen prior to extraction of messenger (m)RNA. Surgical samples of heart valve (n = 6) and papillary muscle (n = 3) were also examined.
Aliquots of purified mRNA were reverse-transcribed for analysis of gene expression by a polymerase chain reaction amplification assay. Primers specific for angiotensinogen, renin, ACE, cardiac chymase, atrial natriuretic peptide, glyceraldehyde-3-phosphate dehydrogenase, adenosine deaminase and the transferrin receptor were used for a qualitative analysis of co-expression of these genes within the same sample. In a subgroup of eight patients, a quantitative comparison of the relative levels of ACE gene expression was performed using a competitive polymerase chain reaction.
Angiotensinogen and ACE expression were detected in all atrial, valve and ventricular samples examined, at levels similar to those of 'housekeeping' genes such as the transferrin receptor. Atrial renin and chymase expression were more difficult to detect, being demonstrable in only 70 and 63% of the samples, respectively. Higher levels of chymase were detected in ventricular samples than in atrial tissues. A quantitative analysis of ACE expression in eight atrial samples provided evidence of interindividual variation in the relative level of atrial ACE expression.
The essential components of the renin-angiotensin system are co-expressed at a low level in the right atrial appendage and are detectable in other regions of the human heart. Renin and chymase genes are expressed at a lower level than the angiotensinogen and ACE genes and exhibit regional differences in expression. Interindividual variation in the relative level of ACE expression can be detected by a competitive polymerase chain reaction.
检测编码肾素 - 血管紧张素系统各组分的基因的共表达情况，并研究心脏手术患者右心耳中血管紧张素转换酶（ACE）基因表达水平的潜在变异。
手术时从30例随机选取的患者中采集右心耳，并在提取信使（m）RNA之前迅速在液氮中冷冻。还检查了心脏瓣膜（n = 6）和乳头肌（n = 3）的手术样本。
将纯化的mRNA等分试样进行逆转录，通过聚合酶链反应扩增测定法分析基因表达。使用针对血管紧张素原、肾素、ACE、心脏糜酶、心房利钠肽、甘油醛 - 3 - 磷酸脱氢酶、腺苷脱氨酶和转铁蛋白受体的特异性引物，对这些基因在同一样本中的共表达进行定性分析。在8例患者的亚组中，使用竞争性聚合酶链反应对ACE基因表达的相对水平进行定量比较。
在所检查的所有心房、瓣膜和心室样本中均检测到血管紧张素原和ACE的表达，其水平与转铁蛋白受体等“管家”基因的水平相似。心房肾素和糜酶的表达更难检测到，分别仅在70%和63%的样本中可检测到。在心室样本中检测到的糜酶水平高于心房组织。对8个心房样本中ACE表达的定量分析提供了心房ACE表达相对水平存在个体间变异的证据。
肾素 - 血管紧张素系统的基本组分在右心耳中低水平共表达，并且在人类心脏的其他区域也可检测到。肾素和糜酶基因的表达水平低于血管紧张素原和ACE基因，并且在表达上存在区域差异。通过竞争性聚合酶链反应可检测到ACE表达相对水平的个体间变异。
