Association of essential hypertension in elderly Japanese with I/D polymorphism of the angiotensin-converting enzyme (ACE) gene

Recent evidence suggests that an insertion/deletion (I/D) polymorphism of the gene encoding angiotensin-converting enzyme (ACE) is associated with myocardial infarction and related cardiovascular diseases. We investigated a possible association of the ACE polymorphism with essential hypertension in a total of 263 cases/controls from among the elderly (age, over 70 years) and middle-aged (age between 30 and 60 years) Japanese population. The frequency of the I/I homozygote was significantly higher in hypertensive subjects than in controls in the elderly age group (33/57 vs 16/46; P = 0.02), but no association was observed in the middle-aged group (25/75 vs 26/85; P = 0.71). Similarly, having at least one insertion allele was associated with essential hypertension in the elderly age group (83/114 vs 46/92 in controls; P = 0.001), but not in the middle-aged group (78/150 vs 94/170; P = 0.524). These data suggest that genetic variation at the ACE locus may be associated with some determinants for blood pressure in elderly persons, and imply the involvement of the ACE insertion/deletion polymorphism in the etiology of age-related essential hypertension in the Japanese population. Received: April 18, 2000 / Accepted: July 25, 2000     

Induction of cardiac angiotensin I-converting enzyme with dietary NaCl-loading in genetically hypertensive and normotensive rats

We have recently shown that the angiotensin I converting enzyme (ACE) gene is linked to NaCl-loaded blood pressure in the stroke-prone spontaneously hypertensive rat (SHRSP), and that high-NaCl loading selectively stimulates ACE in the aorta of SHRSP but not in normotensive Wistar-Kyoto (WKY) rats. We therefore investigated the relationship between cardiac ACE and the development of hypertension and left ventricular hypertrophy in response to normal- and high-NaCl diet in these rats. ACE mRNA and ACE activity were measured in left ventricular tissue after completion of hemodynamic characterization of the animals. While SHRSP rats increased blood pressure (P<0.0001) and heart rate (P<0.005) in response to high NaCl, blood pressure remained unchanged in WKY. Similarly, relative left ventricular weight increased only in SHRSP after high NaCl (P<0.002). A significant two- to threefold increase of cardiac ACE mRNA and fourfold stimulation of ACE enzyme activity in response to high NaCl was found in both WKY and SHRSP rats (P<0.005). The induction of ACE gene expression was significantly more pronounced in SHRSP compared to WKY (P<0.02), whereas no significant strain differences in left ventricular ACE activity were found after either normal- or high-NaCl diet. Thus, arterial blood pressure and left ventricular weight remained unchanged in the WKY rats despite the activation of left ventricular ACE activity after high-NaCl exposure. These results demonstrate that left ventricular ACE activity is equally upregulated in response to high-NaCl in the normotensive and hypertensive strain, independently from the development of hypertension. We conclude that the pretranslational induction of left ventricular ACE with high-NaCl loading may be important both for the regulation of cardiac angiotensins and kinins and for local therapeutic ACE inhibition in the heart during high-salt status.Abbreviations ACE Angiotensin I-converting enzyme - Ang Angiotensin - LVH Left ventricular hypertrophy - PCR Polymerase chain reaction - SHRSP Stroke-prone spontaneously hypertensive rat - WKY Wistar-Kyoto     

A prospective evaluation of the angiotensin-converting enzyme D/I polymorphism and left ventricular remodeling in the 'Healing and Early Afterload Reducing Therapy' study

The D/I (deletion, D, insertion, I) polymorphism of the angiotensin-converting enzyme (ACE) gene has been extensively studied for its association with a number of cardiovascular and other disease states. However, its potential association with differential clinical efficacy of ACE inhibitors (ACE-I) administered to patients who had suffered a myocardial infarction (MI), i.e. the prevention of left ventricular (LV) remodeling, has so far not been specifically studied. The aim of the study was to investigate whether the D/I polymorphism of the ACE gene is associated with the incidence of post-MI LV remodeling in patients drawn from the 'Healing and Early Afterload Reducing Therapy' (HEART) Study. The ACE D/I polymorphism was characterized by the polymerase chain reaction (PCR) in 265 subjects from the 'Healing and Early Afterload Reducing Therapy' Study, a double-blind, placebo-controlled trial with the objective of determining whether early or delayed administration of the ACE-I, ramipril, in patients with acute anterior wall MI would be optimal in reducing LV enlargement. Selected frequencies for the ACE D and I alleles were 0.59 and 0.41 (placebo-high dose group), 0.56 and 0.44 (low dose-low dose group), and, 0.60 and 0.40 (high dose-high dose group), respectively. All observed genotype frequencies were in Hardy-Weinberg equilibrium. There was no evidence for an association between genotype and outcome regarding LV size or function, nor with the initial blood pressure response after ACE-I administration (adjusted for covariates). Our data provide no evidence for an association of the ACE D/I polymorphism with the risk of LV remodeling post-MI in the presence of ACE-I therapy, and therefore do not suggest that differential clinical efficacy of ACE-inhibitors is related to this genetic marker.     

血管紧张素I转换酶基因多态性与糖尿病视网膜病和糖尿病心肌梗塞关联

目的探讨血管紧张素Ⅰ转换酶(angiotensin Ⅰ-converting enzyme, ACE)基因多态性与糖尿病视网膜病和心肌梗塞之间的关联性.方法应用PCR技术,对1型糖尿病33例视网膜病患者和36例非视网膜病患者、2型糖尿病68例伴心肌梗塞患者和57例伴视网膜病患者以及190例无并发症患者的ACE基因插入/缺失型多态性进行了检测.结果 ACE基因与视网膜病之间无关联.而2型糖尿病心肌梗塞患者与非心肌梗塞患者比较, DD纯合子频率显著增高(41.2% vs 33.2%),D等位基因频率也显著增高,差异有显著性(P<0.05).结论 D等位基因(相对风险为1.50)和DD基因型(相对风险为1.33)可能是2型糖尿病心肌梗塞发生的风险因子.     

血管紧张素Ⅰ转换酶基因多态性与糖尿病视网膜病和糖尿病心肌梗塞关联

目的　探讨血管紧张素 转换酶 ( angiotensin - converting enzyme,ACE)基因多态性与糖尿病视网膜病和心肌梗塞之间的关联性。方法　应用 PCR技术 ,对 1型糖尿病 33例视网膜病患者和 36例非视网膜病患者、2型糖尿病 6 8例伴心肌梗塞患者和 5 7例伴视网膜病患者以及 190例无并发症患者的ACE基因插入 /缺失型多态性进行了检测。结果　 ACE基因与视网膜病之间无关联。而 2型糖尿病心肌梗塞患者与非心肌梗塞患者比较 ,DD纯合子频率显著增高 ( 4 1.2 % vs 33.2 % ) ,D等位基因频率也显著增高 ,差异有显著性 ( P<0 .0 5 )。结论　 D等位基因 (相对风险为 1.5 0 )和 DD基因型 (相对风险为 1.33)可能是 2型糖尿病心肌梗塞发生的风险因子     

A study of gene--environment interaction on the gene for angiotensin converting enzyme: a combined functional and population based approach

Introduction: Studies on the role of the insertion/deletion (I/D) polymorphism of the gene coding for angiotensin converting enzyme (ACE) in atherosclerosis have been inconsistent. In a meta-analysis, we recently showed that this relationship is stronger in high risk populations. In this paper, we used a combined functional and population based approach to investigate the gene–environment interaction of the ACE I/D polymorphism in relation to carotid artery wall thickness.

Methods: The study was part of the Rotterdam Study, a prospective population based cohort study. In 5321 subjects, IMT was measured in the carotid arteries by ultrasonography and ACE genotype was determined by size analysis of polymerase chain reaction products.

Results: In multiple regression analysis, I/D polymorphism and smoking were the main determinants for plasma ACE activity (r² = 0.28). There was a positive association between the D allele of the I/D polymorphism and carotid artery thickness among current smokers (p = 0.03). Subjects carrying only one of the risk factors (smoking or the D allele) did not show significant differences in IMT compared with the non-/former smokers group carrying two II alleles, while carriers of both risk factors had significant higher IMT. The association was not present in non-/former smokers.

Discussion: The results provide further evidence that genetic and environmental factors interact in the formation of the arterial lesions. This study shows that large population based studies can be extremely helpful in unravelling the genetic origin of complex diseases such as atherosclerosis.

     

The D-allele of ACE insertion/deletion polymorphism is associated with regional white matter volume changes and cognitive impairment in remitted geriatric depression

Prior studies suggested that angiotensin-converting enzyme (ACE) affected vascular homeostasis and degradation of amyloid β (Aβ). It is associated with the therapeutic outcome in major depression. The aim of this study was to investigate the association between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and structural abnormalities in remitted geriatric depression (RGD), and test the relationship of neuropsychological performances and regional white matter volumes. 31 RGD patients were recruited and neuropsychological tests, magnetic resonance imaging (MRI) and genotype of ACE I/D were examined for each subject. The differences in regional white matter volume were tested between I homozygotes and D-allele carriers (I/D or D/D genotype) by optimized VBM. D-allele carriers exhibited significantly smaller white matter volumes of right superior frontal gyrus (SFG) and right anterior cingulated gyrus (ACG), but had larger volumes of left middle temporal gyrus (MTG) and right middle occipital gyrus (MOG) than I homozygotes (P < 0.001). Meanwhile, there was a significant positive correlation between white matter volume enlargement of left MTG and Symbol Digit Modalities Test (SDMT) (r = 0.456, P = 0.043), and the reduction of right ACG was negatively related to Clock Drawing Test (CDT) performance (r = −0.445, P = 0.050) in D-allele carriers. The finding suggests that ACE can modulates the pathology of RGD, the left MTG and right ACG might be involved in the pathophysiology of cognitive dysfunction in RGD patients.     

A study of the relationships between angiotensin- converting enzyme gene, chymase gene polymorphisms, pharmacological treatment with ACE inhibitor and regression of left ventricular hypertrophy in essential hypertension patients treated with benazepril

BACKGROUND: About 15-37% of the adult population worldwide suffers from hypertension. Hypertension is responsible for one-third of all global deaths. Left ventricular hypertrophy (LVH) is one of the most important characteristics of hypertension target organ damage and is also an independent risk factor for cardiovascular events. Therefore, effective regression of LVH is a main aim of hypertension treatment and also an important public health concern. However, few studies of the regression of LVH have been reported. In particular, little is known about the relationship between the genotypes of angiotensin-converting enzyme (ACE) and chymase (CMA) genes, and the effectiveness of antihypertensive drugs in regression of LVH. AIM: The study investigated whether the insertion/deletion (I/D) polymorphism of ACE gene and the A/B polymorphism of the CMA gene are related to the regression of LVH in essential hypertension patients who were participants in a long-term trial of therapy with benazepril. SUBJECTS AND METHODS: Data from 157 patients was collected and used in the analysis. The genotypes of ACE and CMA genes were identified by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Left ventricular mass (LVM) was measured by echocardiography, and left ventricular mass index (LVMI) was calculated. RESULTS: Blood pressure was markedly reduced and heart rate was unchanged by long-term treatment with benazepril. Regression of LVH was observed. The mean reduction in LVMI was 41.50+/-28.48 g m-2. Reduction of LVM, LVMI and percentage reduction of LVMI were more in the DD group than in the II and ID groups (P<0.05). No significant difference in other indices was found in the different genotype groups of ACE (P>0.05). No significant difference in all indices was found among the different genotype groups of CMA (P>0.05). No interaction was found between the genotypes of ACE and CMA. CONCLUSION: Hypertension patients with the DD genotype are more likely to have regression of LVH when treated with benazepril than patients with other genotypes of ACE. No evidence was found to support an association between CMA genotype and regression of LVH in patients or to support the interaction between the two genes in regression of LVH.     

The ACE I allele is associated with increased risk for ruptured intracranial aneurysms

Genetic and environmental factors play roles in the aetiology of ruptured intracranial aneurysms. Hypertension has been reported as a risk factor for intracranial aneurysm haemorrhage. We have tested if genotypes at the angiotensin converting enzyme (ACE) gene locus are associated with ruptured intracranial aneurysms. The insertion/deletion polymorphism in the ACE gene was genotyped in 258 subjects presenting in East Anglia with ruptured intracranial aneurysms (confirmed at surgery or angiographically) and 299 controls from the same region. ACE allele frequencies were significantly different in the cases and the controls (alleles χ²₁=4.67, p=0.03). The I allele was associated with aneurysm risk (odds ratio for I allele v D allele = 1.3 (95% CI=1.02-1-65); odds ratio for II v DD genotype = 1.67 (95% CI=1.04-2.66)). The I allele at the ACE locus is over-represented in subjects with ruptured intracranial aneurysms. These data are supported by non-significant trends in the same direction in two previous smaller studies. Thus, this allele may be associated with risk for ruptured intracranial aneurysms.


Keywords: ACE I allele; ruptured intracranial aneurysms     

Angiotensin converting enzyme gene polymorphism and cardiovascular morbidity and mortality: the Rotterdam Study

Background: Findings on the association between the insertion/deletion (I/D) polymorphism of the angiotensin I-converting enzyme (ACE) gene and cardiovascular morbidity and mortality have been inconsistent. Considering the possible interaction between this polymorphism and smoking, we evaluated the association between ACE I/D polymorphism and myocardial infarction (MI), mortality due to coronary heart disease (CHD), and cardiovascular disease (CVD).

Methods: The study was performed within the Rotterdam Study, a population based cohort study. The ACE I/D polymorphism was determined for 6714 participants and smoking status recorded at baseline. Fatal and non-fatal MIs and mortality events were regularly recorded. Cox proportional hazard analysis was performed separately for current smokers and non-smokers. We used age as the follow up time, presenting age specific survivals.

Results: During follow up, 248 MIs and 301 and 482 deaths, respectively, due to CHD and CVD occurred. There were no significant differences between the genotypes as regards MI incidence. Among smokers, there was an increased risk of CHD and CVD mortality in carriers of the DD genotype compared to the II genotype, which diminished at later ages (p<0.01 for gene-age interaction). Subgroup analysis in a younger and older group (based on the median age of 68.2 years) showed a significantly increased risk of CVD mortality in the younger group (hazard ratio = 5.19; 95% confidence interval: 1.15 to 23.42).

Conclusions: This study showed that the ACE I/D polymorphism is not a strong risk factor for MI but its interaction with smoking might play a role in cardiovascular mortality especially at younger ages.

     

Polymorphisms in the Angiotensin Converting Enzyme Gene and Growth in the First Year of Life

Abnormal patterns of fetal and infant growth have been associated with an increased risk of cardiovascular disease in adulthood. Catch‐up growth during the first year of life has been associated with a higher prevalence of type 2 diabetes mellitus, whereas a lack of catch‐up growth tracks with a risk of hypertension. The role of genetic factors influencing both growth and blood pressure have not been explored. We genotyped cord blood samples from 530 singleton, Caucasian, uncomplicated pregnancies, drawn from a larger cohort of 1650 pregnancies, and related polymorphism in the angiotensin converting enzyme (ACE) gene (alleles insertion (I) or deletion (D)) with measures of size at birth and at age of 1 year. ACE genotype did not significantly influence size at birth, although there was a greater proportion of individuals with the D/D genotype born with a birth weight less than the 10^th centile (P = 0.004). The ACE I/I genotype was significantly associated with higher weight (p = 0.001), body mass index (p = 0.001) and mid arm circumference (p = 0.001) at 1 year of age compared to the ACE D/D and I/D genotypes. Individuals with the I/I genotype displayed catch‐up (gain from birth size of ≥0.6 Standard Deviation Score) in weight (p = 0.04), body mass index (p = 0.03) and mid arm circumference (p = 0.03) compared to the D/D group, the majority of which showed no change or catch‐down. The I/D genotype was distributed equally across the catch up/catch down/no change categories. The effect was more marked in males, but ACE genotype and sex of the infant contributed independently to mid arm circumference measurements and there was no interaction between the two. There was no effect of maternal or paternal ACE genotype on birth size. In a multiple linear regression model ACE genotype, socioeconomic status and sex of the infant explained 10.9% of the variance in body mass index SDS at 1 year of age. We conclude that the ACE I/I genotype is associated with a higher weight and body mass index SDS at 1 year of age, along with catch‐up in terms of these measures from birth to 1 year. The D/D genotype is associated with a greater proportion of babies, born at term, that at small for gestational age. These results suggest that due consideration should be given to the underlying genotype of an individual when evaluating the association of early human growth with the development of risk factors for cardiovascular disease. The observation of independent effects of genotype, sex of the individual and socioeconomic status on postnatal growth suggests the need to develop methodologies for the integration of genetic and environmental factors in causality modelling.     

Association of angiotensin-converting enzyme insertion/deletion polymorphism with obesity,cardiovascular risk factors and exercise-mediated changes in Korean women

This study examined whether the angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) polymorphism is associated with obesity, cardiovascular risk factors and 12-week exercise-mediated changes in Korean women. A total of 105 subjects were divided into three groups as II, ID and DD genotype groups based upon ACE I/D genotypes. Body composition and cardiovascular risk factors were compared among the three groups, and the association of ACE I/D genotypes with obesity and hypertension was evaluated. Total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) levels were higher (P < 0.05) in the DD genotype than in II or ID genotypes. D allele frequency in ACE I/D gene had a higher (P = 0.063) trend in the hypertensive group than the normotensive group. The DD genotype had a trend to develop (odds ratio 4.032, P = 0.086) more hypertension than the II genotype. The II and ID genotypes showed a significant (P < 0.05) decrease in intima media thickness of the carotid artery after an exercise intervention, whereas the DD genotype showed an increase. In conclusion, there is a trend towards association of ACE I/D polymorphism with hypertension but not with obesity. Exercise-mediated changes did not differ significantly among genotypes except IMTCA.     

ACE/DD基因型和MYH7突变与原发性高血压左室肥厚的关系

 目的 探讨ACE/DD基因型与MYH7突变联合作用和高血压左室肥厚（LVH）的关系。方法 对102例高血压LVH患者与101例高血压非LVH患者以及100例正常对照进行病例-对照研究。超声心动图测量和计算左室重量指数（LVMI）。用聚合酶链反应（PCR）、限制性片段长度多态性（RFLP）检测ACE/ID多态性,双脱氧末端测序方法检测MYH7基因突变。结果 高血压LVH组ACE基因DD基因型频率显著高于高血压非LVH组和正常对照组（P<0.01）;MYH7基因未发现突变。结论 ACE基因多态性与高血压LVH形成有关,DD基因型易发生左心室肥厚。MYH7基因突变与高血压LVH无明显关系,ACE基因DD基因型与MYH7基因间不存在联合作用。     

Polymorphism of genes of the renin-angiotensin system ACE, ATIR, and AT2R in patients with pulmonary tuberculosis

The investigation was aimed at testing the hypothesis on the possible role of some genes of the renin-angiotensin system in the formation of innate immunity to tuberculosis. It is known that insertion-deletion (I/D) polymorphism of the gene encoding the angiotensin-converting enzyme (ACE) influences the concentration of angiotensin II in the human organism and, indirectly, many stages of metabolism. On one hand, homozygotes of deletion in the ACE gene (DD genotype) are characterized with obesity, arterial hypertension, hypocholesterolemia, and some other pathological conditions. On the other hand, it was demonstrated that hypercholesterolemia is common pathology for patients with pulmonary tuberculosis (C. Perez-Guzman et al., 2005). The investigation of insertion-deletion polymorphism of the ACE gene (genotypes DD, ID and II), single nucleotide polymorphism at position 1166 of the AT1R gene (1166 A/C), and analogous transversion at position 3123 of the AT2R gene (3123 A/C) was carried out. A group of 200 patients with tuberculosis 202 patients with essential hypertension and 208 healthy individuals were analyzed. A group of patients with essential hypertension was used as a contrast sample. According to hypothesis, a statistically significant excess number was found of carriers of genotype DD (ACE) in patients with hypertension as compared to the group of patients with tuberculosis (χ² = 9.64; ρ = 0.0019; OR = 2.0; CI 1.2, 3.3). The tendency toward an increase in the amount of DD genotypes was observed in comparisons of patients with tuberculosis and healthy patients with hypertension, although these differences did not reach significant values in the given study. A comparison of genotypes and allelotypes in group of patients with tuberculosis and both control groups (healthy and patients with hypertension) was performed. A significant difference was observed in the group of male patients with tuberculosis, though not female, when comparing with control groups. It had been demonstrated that the most important contribution is made by the ACE and AT2R genes. Genotype ID + 3123C (genes ACE and AT2R) was found significantly more often in male patients with tuberculosis than in the control group of healthy individuals (χ² = 9.70; ρ = 0.002; OR = 2.3; CI 1.2s-4.3). The obtained results were discussed.     

血管紧张素转化酶基因多态性与高血压病合并脑梗塞的探讨

目的探讨血管紧张素转化酶（ＡＣＥ）基因插入／缺失（Ｉ／Ｄ）多态性与中国人高血压病合并脑梗塞的关系。方法应用聚合酶链反应（ＰＣＲ）方法检测６２例正常人，５５例高血压病无心脑血管合并症患者，４４例高血压病合并脑梗塞患者的ＡＣＥ基因型。结果ＡＣＥ基因Ｉ／Ｄ多态性与高血压病无相关关系。但高血压合并脑梗塞的ＤＤ基因型频率２９．６％及Ｄ等位基因频率５６．８％显著高于正常对照组的１２．９％和３８．７％（分别Ｐ＜０．０５和Ｐ＜０．０１），以及高血压无心脑血管合并症组的１２．８％和４０％（分别Ｐ＜０．０５，Ｐ＜０．０２）。结论ＡＣＥ基因缺失型可能是中国人高血压病合并脑梗塞发病的重要遗传因素     

The angiotensin-I converting enzyme I/D polymorphism is not associated with type 2 diabetes in individuals undergoing coronary angiography. (The Ludwigshafen Risk and Cardiovascular Health Study)

The deletion (D) allele of the angiotensin-I converting enzyme (ACE) is associated with higher ACE activity and has been implicated only recently in the pathogenesis of type 2 diabetes in Caucasian subjects. We have studied the ACE I/D polymorphism in 1054 patients with type 2 diabetes and in 2251 individuals without type 2 diabetes in Caucasians persons undergoing coronary angiography. Further parameters of glucose metabolism (fasting glucose, HbA1c, insulin, C-peptide, pro-insulin, and pancreatic beta-cell function) were analyzed according to the ACE I/D genotype in a subgroup of 2000 individuals in whom an oral glucose challenge was performed. The genotypes ACE II, ID, DD occurred at similar frequencies in patients with type 2 diabetes mellitus (21.0, 50.8, and 28.3%, respectively) compared to non-diabetic individuals (23.3, 49.2, and 27.5%, respectively). There was no association of the ACE D allele with all type 2 diabetes mellitus (OR 1.16, 95%CI, 0.94-1.43), nor with known (OR 1.28, 95% CI, 0.99-1.68) or newly diagnosed diabetes (OR 1.00, 95% CI, 0.75-1.32). These findings were not materially altered when we adjusted for age and gender, cardiovascular risk factors and anti-diabetic or cardiovascular medication. Further the ACE D-allele was not associated with angiographic coronary heart disease or myocardial infarction. The ACE I/D genotype is not associated with type 2 diabetes mellitus, glucose metabolism, coronary heart disease, or myocardial infarction.     

Influences of the G2350A polymorphism in the ACE Gene on cardiac structure and function of ball game players

Background  

Except for the I/D polymorphism in the angiotensin I-converting enzyme (ACE) gene, there were few reports about the relationship between other genetic polymorphisms in this gene and the changes in cardiac structure and function of athletes. Thus, we investigated whether the G2350A polymorphism in the ACE gene is associated with the changes in cardiac structure and function of ball game players. Total 85 healthy ball game players were recruited in this study, and they were composed of 35 controls and 50 ball game players, respectively. Cardiac structure and function were measured by 2-D echocardiography, and the G2350A polymorphism in the ACE gene analyzed by the SNaPshot method.     

血管紧张素转化酶基因I/D多态性与脑梗死后抑郁相关

目的 探讨北京地区汉族人群血管紧张素转化酶(ACE)基因插入/缺失(I/D)多态性与脑梗死后抑郁(PCID)发病的关系.方法 用汉密尔顿抑郁量表评定664例脑梗死患者抑郁状态,用PCR方法检测患者ACE基因I/D多态性,分析基因多态性分布与脑梗死后抑郁发病的相关性.结果 脑梗死后抑郁患者组ACE基因I/I基因型频率和I等位基因频率(分别为0.388和0.549)显著高于脑梗死后非抑郁患者对照组(C)(分别为0.286和0.481,P＜0.05).结论 ACE基因I/D多态性与脑梗死后抑郁发病相关,ACE I/I基因型可能是脑梗死后抑郁发病的危险因素.     

Renin-angiotensin system and myocardial collagen matrix remodeling in hypertensive heart disease: in vivo and in vitro studies on collagen matrix regulation

Summary The interstitial space of the myocardium is composed of nonmyocyte cells and a highly organized collagen network which serves to maintain the architecture and mechanical behavior of the myocardial walls. It is the myocardial collagen matrix that determines myocardial stiffness in the normal and structurally remodeled myocardium. In hypertensive heart disease, the heterogeneity in myocardial structure, created by the altered behavior of nonmyocyte cells, particularly cardiac fibroblasts which are responsible for collagen synthesis and degradation, explains the appearance of diastolic and/or systolic dysfunction of the left ventricle that leads to symptomatic heart failure. Several lines of evidence suggest that circulating and myocardial renin-angiotensin systems (RAS) are involved in the regulation of the structural remodeling of the nonmyocyte compartment, including the cardioprotective effects of angiotensin converting enzyme (ACE) inhibition that was found to prevent myocardial fibrosis in the rat with renovascular hypertension. In cultured adult rat cardiac fibroblasts angiotensin II was shown to directly stimulate collagen synthesis and to inhibit collagenase activity, which is the key enzyme for collagen degradation, that would lead to collagen accumulation. In the spontaneously hypertensive rat, an appropriate experimental model for primary hypertension in man, left ventricular hypertrophy could be regressed and abnormal myocardial diastolic stiffness due to interstitial fibrosis could be restored to normal by inhibition of the myocardial RAS. These antifibrotic or cardioreparative effects of ACE inhibition that occurred irrespective of blood pressure normalization may be valuable in reversing left ventricular diastolic dysfunction in hypertensive heart disease.     

The effect of non-antihypertensive doses of angiotensin converting enzyme inhibitor on myocardial necrosis and hypertrophy in young rats with renovascular hypertension

In renovascular hypertensive rats, low doses of angiotensin converting enzyme (ACE) inhibitors have been found to prevent myocardial hypertrophy independent of blood pressure level. This finding would suggest humoral rather than mechanical control of myocyte growth. The aim of this study was to examine the effect of nonantihypertensive doses of ACE inhibitor on myocardial hypertrophy and necrosis in hypertensive rats. Renovascular hypertension (RHT) was induced in four-week-old Wistar rats. Twenty-eight animals were treated for four weeks with three doses of ramipril (0.01, 0.1 or 1.0 mg/kg/day, which are unable to lower blood pressure. Fourteen animals were not treated (RHT group). A sham operated, age/sex-matched group was used as control ( n  = 10). Myocardial histology was analysed in 3 μm thick sections of the ventricle stained with either haematoxylin-eosin, reticulin silver stain or Masson's trichrome. There was a significant correlation between systolic blood pressure and left ventricular to body weight ratio in both sets of animals: untreated plus controls and ramipril-treated rats. ACE inhibition prevented myocyte and perivascular necrosis and fibrosis in a dose-dependent manner. We conclude that myocardial hypertrophy in rats with renovascular hypertension is directly related to arterial pressure, and that this relationship is not affected by nonantihypertensive doses of ACE inhibitor. Myocardial necrosis/fibrosis and coronary artery damage induced by angiotensin II are prevented by ACE inhibitor in a dose-dependent manner, despite the presence of arterial hypertension.