(Stroke. 1996;27:435-440.)
© 1996 American Heart Association, Inc.
Articles |
Angiotensin-Converting Enzyme Insertion/Deletion Polymorphism and Cerebrovascular Disease
From the Diabetes and Thrombosis Research Group, Division of Medicine, University of Leeds, Leeds General Infirmary; and the Department of Neurology, St James's University Hospital (J. Bamford), Leeds, UK.
Correspondence to Dr A. Catto, Diabetes and Thrombosis Research Group, Division of Medicine, University of Leeds, Leeds General Infirmary, Leeds, LS1 3EX, UK. E-mail andrewc@pathology.leeds.ac.uk.
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Abstract |
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 Top Abstract IntroductionSubjects and Methods Results Discussion References |
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Background and Purpose There is evidence that an allelic variation in the angiotensin-converting enzyme (ACE) gene may confer an increased risk of vascular disease. The roles of the ACE insertion/deletion polymorphism and circulating ACE levels are unknown in cerebrovascular disease.
Methods We studied an insertion/deletion polymorphism within intron 16 of the ACE gene by polymerase chain reaction and plasma ACE activity in 467 cases of stroke, the pathological type of which was established by cranial CT, and 231 control subjects. ACE genotype and activity were related to stroke type and mortality at 4 weeks and 3 months.
Results No difference in genotype frequency was observed between all subjects with stroke and control subjects or between control subjects and subjects with cerebral infarction or cerebral hemorrhage. Plasma ACE activity was significantly lower in stroke patients at presentation (64.1 IU/L) than in control subjects (79.6 IU/L; P<.0001). Twenty-one patients (4.5%) with cerebral infarction died within 4 weeks and 56 patients (12%) within 3 months. These patients had significantly lower plasma ACE activity than patients who survived. There was some evidence that risk of death within 4 weeks increased with the number of D alleles (P=.02). Among survivors, plasma ACE activity showed a mean increase of 6.9 IU/L (95% confidence interval, 3.0 to 10.8) between levels at presentation and at 3 months (73.6 IU/L), the latter being similar to ACE activity in control subjects.
Conclusions Low ACE activity at stroke presentation and possession of the D allele may be associated with increased risk of early death from acute cerebral infarction.
Key Words: cerebrovascular disorders • genetics • mortality • angiotensin-converting enzymes
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Introduction |
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TopAbstractIntroductionSubjects and Methods Results Discussion References |
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Angiotensin-converting enzyme is a dipeptidyl carboxylase that activates angiotensin I through cleavage of the carboxyterminal dipeptide. ACE metabolizes the vasoactive peptides angiotensin II and bradykinin, which are mediators of vascular tone and smooth muscle cell proliferation.1 Experimental data suggest that in the presence of high levels of plasma ACE, opposing effects of these peptides result in vascular wall thickening and contribute to the development of vascular disease.2
In vitro autoradiography and immunohistochemical studies have mapped ACE within the brain,3 with high concentrations of ACE being found in the nigrostriatal pathway and basal ganglia.4 The major sources of circulating ACE are endothelial cells, although tissue ACE, as opposed to circulating plasma ACE, might contribute to vasoactive peptide metabolism. Plasma ACE activity shows considerable interindividual variation, although intraindividual variations are small.5 No environmental mediators of circulating ACE are recognized, although certain disease states are associated with elevated ACE activity. The Etude Cas-Temoins sur l'Infarctus du Myocarde (ECTIM) study data suggested that elevated ACE activity among younger subjects was associated with a higher risk of myocardial infarction.6 In stroke, ACE activity has not been described in either cerebral infarction or cerebral hemorrhage, and no measurements have been made of ACE activity in the acute and convalescent phases of stroke. The contribution of ACE activity to the development of cerebrovascular disease remains undetermined.
Cloning of the human ACE gene allowed the detection of a polymorphism, which consists of the presence (insertion, I) or absence (deletion, D) of a 250-bp fragment.7 The DD genotype has been associated with a number of cardiovascular diseases. Cambien and coworkers8 demonstrated an excess of the DD genotype in subjects regarded as being at low risk for myocardial infarction. The genotype has also been described in subjects with dilated and ischemic cardiomyopathy9 and in association with elevated fasting glucose.10 In Western populations, ACE genotype has not been shown to be related to the development of human hypertension,11 although early animal studies in stroke-prone hypertensive rats showed an association with the ACE locus.12 Recently the DD genotype has been linked with the development of left ventricular hypertrophy,13 although this association has been disputed.14 Any possible association of the ACE genotype with stroke pathogenesis would be important, particularly since hypertension is a major risk factor for stroke, second only to advancing age. It is important to recognize that any study must attempt to deal with the lack of pathological homogeneity underlying "stroke." In this study subjects were classified by CT into infarct or hemorrhage groups. Subjects with infarction were then subclassified by standard criteria into those in whom intrinsic small-vessel disease was the most likely etiologic mechanism (LACI) and others in whom larger-vessel disease (either precerebral, aortic, or cardiac) was the most likely mechanism.
The primary aims of this study were to determine the frequency of certain ACE genotypes among subjects with the phenotypes cerebral infarction and PICH and to determine ACE activity at the time of acute stroke and after 3 months. The secondary aim was to determine the relationships between ACE genotype, ACE activity, and mortality after 4 weeks (early) and 3 months.
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Subjects and Methods |
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TopAbstractIntroductionSubjects and Methods Results Discussion References |
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Subjects
We studied 499 white patients presenting with acute stroke as defined by the World Health Organization15 (but excluding patients with primary subarachnoid hemorrhage) who were inpatients in any one of four acute-care hospitals in Leeds. The patients normally resided within the boundary of the Leeds Family Health Services Authority and were part of a cohort study examining the role of genotypes and hemostatic factors in the development of cerebrovascular disease. Informed consent was obtained from the case and control subjects, according to a protocol approved by the hospitals' Research Ethics Committees. A detailed clinical questionnaire, including information on vascular risk factors, and a physical examination were completed by a single examiner (A.C.) for each case. Data were validated with reference to hospital case notes, primary care records, and dialogue with family members. The presence of hypertension was defined as preadmission blood pressures of 160/95 mm Hg or greater as recorded in the primary care record. A history of ischemic heart disease was assessed with the use of the Rose questionnaire16 and with reference to previous electrocardiograms and laboratory data. A history of peripheral vascular disease was established by clinical examination, prior angiographic studies, and/or evidence of vascular surgery. Gout was diagnosed on clinical grounds with reference to primary care records. Current and previous smoking habits were recorded.
Noncontrast cranial CT was performed for each patient to determine the stroke phenotype (infarction or hemorrhage). Cases of cerebral infarction were subclassifed independently and without knowledge of cranial CT result by two of us (J.B. and A.C.) according to the Oxfordshire Community Stroke Project classification17 into those with probable small-vessel disease (LACI), those with probable large-vessel disease (TACI or PACI), and those with PICH. Results of admission chest radiography and electrocardiograms were noted.
Uncuffed venous blood samples were drawn from each subject within 10 days (mean, 2 days) of the stroke onset for extraction of DNA and plasma ACE activity estimation. We did not measure ACE activity in the first 114 subjects. Plasma ACE activity was reestimated 3 months later at a follow-up visit. When samples were not obtained at follow-up, this was the result of changed domicile, address not traced, or failed blood sampling. All cases were "flagged" at study entry and their National Health Service number verified on the Leeds Family Health Services Authority database. Deaths were notified by the Office of Population Censuses and Surveys.
White control
subjects of European descent were randomly selected from
general practice registers from the same geographic locality as the
case subjects. Control subjects were healthy and believed free of
significant vascular disease. Control subjects received a standard
invitation by mail to collaborate, 62% of whom agreed to take part.
Basic demographic data were completed for each subject and are shown in
Table 1
. Venous blood samples were treated in a manner similar
to that
used for the case subjects.
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Laboratory Techniques
Leukocyte DNA was extracted from 10 mL
of venous blood,
anticoagulated with 1.6 mg/mL EDTA, by a detergent/salt exchange
method, as described previously.18 The ACE I/D
polymorphism was detected by polymerase chain reaction, according
to the presence or absence of an insertion in intron 16. Polymerase
chain reaction products (490-bp insertion and 190-bp deletion) were
separated by 2% agarose gel electrophoresis, stained with ethidium
bromide, and viewed with UV light. Samples were genotyped
without reference to clinical data. We verified all samples with the
DD genotype by means of a second
insertion-specific amplification (5'-TTTGAGACGGAGTCTCGCTC
-3').19 Two patients were reassigned to an I/D
genotype as a result of this procedure. Plasma ACE activity was
estimated with the use of 5 mL venous blood anticoagulated with lithium
heparin, according to an in-house analysis, against
commercially available standard samples of known ACE activity. Samples
for ACE activity were centrifuged at room temperature, plasma
separated into cryotubes, snap-frozen in liquid nitrogen, and
stored at -40°C. ACE activity was determined by an automated
method, in which hydrolysis by ACE of a synthetic Tris-buffered
substrate, furanocrylol-1-phenylalanyl-glycylglycine (Sigma
Chemical Co), produced a furanocrylol-blocked amino acid and
dipeptide. The decrease in absorbance at 340 nm was a measure of ACE
activity, expressed as international units per liter.
Statistical Methods
Case and control genotype frequencies
were compared by
2 testing. Initial and 3-month ACE activity
levels in patients were compared with levels in control subjects with
the use of z tests. Initial and 3-month levels in patients
were compared by paired t test. ACE activity in stroke
patients on an ACE inhibitor were compared with those not
on an ACE inhibitor by Mann-Whitney U test.
Stroke subtypes and ACE levels were compared with the use of
one-way ANOVA with Scheffé's post hoc comparison. The
effects of ACE genotype and other factors and covariates on ACE
levels were analyzed in a general linear model with the SAS
General Linear Model procedure. A logistic regression model was used to
study the relationship between mortality, genotype, and ACE
activity.
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Results |
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TopAbstractIntroductionSubjects and Methods Results Discussion References |
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Patients and Control Subjects
A total of 467 patients were included in the analysis; 236 patients (50.5%) were female. The stroke was due to cerebral infarction in 418 patients (89.5%) (23 of whom had undergone hemorrhagic transformation at the time of cranial CT scan), and 49 (10.5%) were due to PICH. Details of the patients studied are shown in Table 1
. Thirty-six stroke patients (7.7%) were
being treated with an ACE inhibitor at the time the acute
sample was taken. Samples were obtained from 231 control subjects, of whom 124 were female (53.7%). The median age was 72.5 years (range, 20 to 90 years). ACE levels were measured in 209 control subjects, of whom 6 were on ACE inhibitor therapy. At the time of the analysis, 96 patients had died, 70 within 3 months of admission.
Genotype Frequencies
Genotypes were not available in 13 case
and 16 control
subjects as a result of failed polymerase chain reaction. The
distribution of ACE genotypes in 454 patients with stroke were
as follows: II, 128 (28%); ID, 200 (44%); and
DD, 126 (28%), which was not significantly different from
the distribution in 215 control subjects: II, 50 (23.2%);
ID, 102 (47.4%); and DD, 63 (29.3%)
(2=1.83, 2 df, P=.40). The
patient genotype distribution was not, however, in
Hardy-Weinberg equilibrium (P<.02). There was no difference
in the frequency of each genotype when we compared subjects
with cerebral infarction (n=406; II, 28%; ID,
44%; and DD, 28%) with those with
intracerebral hemorrhage (n=48; II,
35.4%; ID, 43.8%; and DD, 20.8%)
(2=1.92, 2 df, P=.38). No
difference was observed when the frequency of those with probable
small-vessel disease (LACI, n=130) was compared with those with
probable large-vessel disease (TACI/PACI, n=242)
(2=0.53, 2 df, P=.77).
Genotype frequencies by stroke type are presented in
Table 2. When case subjects with a previous history of
cerebrovascular disease including transient cerebral ischemia
and completed stroke (n=130) were compared with those without a
history, there was no difference in genotype frequency
(II, 29.2%; ID, 43.9%; and DD,
26.9% versus II, 27.1%; ID, 45.5%; and
DD, 27.4%, respectively) (2=0.22, 2
df, P=.90). We found no relationship with age at
first stroke by ACE genotype (II, 70.4 years;
ID, 70.9 years; and DD, 70.8 years)
(P=.94).
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ACE Activity
The initial ACE level in patients taking an ACE
inhibitor (n=36) was significantly lower (36.5 IU/L; SD,
34.6) than in those not on an ACE inhibitor (64.1 IU/L; SD,
24.3) (P=.0001). At 3 months after stroke the relationship
persisted. In those still treated with an ACE inhibitor
(n=14), the level had risen to 51.1 IU/L (SD, 40.6) compared with 73.6
IU/L for those untreated (n=149) (P=.02). Subjects
treated
with an ACE inhibitor were excluded from further
analysis. Initial ACE activity (n=302) was significantly lower
in patients (64.1 IU/L) than in control subjects (n=209) (79.6 IU/L)
(P<.0001), although after 3 months (n=149) the values were
similar in patients (73.6 IU/L) and control subjects
(P=.08). In the 149 case subjects who survived for 3 months,
there was a mean increase in ACE level of 6.9 IU/L (95% confidence
interval, 3.0 to 10.8). There was a significant correlation between
initial and 3-month ACE activity (r=.63; 95% confidence
interval, 0.52 to 0.72). We compared ACE activity between cases of
PICH, LACI, TACI, and PACI. Only patients with PICH had a significantly
lower level of ACE activity compared with ACE activity in patients with
LACI (P=.03), although there was a trend to lower levels in
subjects with cortical infarction. However, at 3 months there was no
significant difference in ACE activity between these groups.
The
relationship between genotype and ACE activity at
presentation in case and control subjects was studied.
Initial levels were compared with control levels by including the
patient/control group as a term in a general linear model, in which ACE
levels were the dependent variable. Other terms in the model were
genotype, age, sex, and group/genotype interaction. ACE
genotype (P=.0001), group (P=.0001), and
the interaction term (P=.007) were all significantly
associated with plasma ACE activity. After the other variables were
accounted for, age and sex were not significantly associated. The
interaction term indicates that the relationship between levels and
genotype differs between patients and control subjects, which
can be seen in Table 3. Differences between patients and
control subjects were apparent only for the ID and
DD genotypes.
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Among stroke patients, 10.7% of the variance of initial ACE activity and 14.5% at 3 months were attributable to the ID polymorphism, compared with an estimate of 22.0% of the variance among control subjects. In patients, the relationships between ACE activity and each of the vascular risk factors (ischemic heart disease, diabetes mellitus, vascular disease, a history of gout, and previous or current smoking) were investigated with the use of ANOVA. Genotype, age, and sex were included as covariates. There was no evidence of a relationship with any of the other factors, in particular with ischemic heart disease or diabetes mellitus. No relationship was found with hypertension.
Effect of ACE Genotype and ACE Activity on Stroke
Mortality
Seventy patients (15%) had died within 3 months of
admission.
Logistic regression was applied to assess the effect of age, ACE level,
and genotype on the risk of death during the first 3 months.
Since ACE levels were not available for all cases, the sample was
reduced to 36 deaths and 257 survivors. In the 35 patients with
cerebral infarction, initial mean ACE activity was related to total
mortality (ACE activity, 55.0 IU/L in those who had died by 3 months
after stroke and 65.7 IU/L in those who survived; P=.02 in
the logistic model). The 3-month mortality was not significantly
related to ACE genotype (P=.13).
Deaths occurring
within 4 weeks are more likely to result directly from
the acute stroke. Only 21 such deaths were recorded among patients
with cerebral infarction, with ACE levels available in 13 of these.
Logistic regression modeling showed that genotype was
associated with increased risk of early death (P=.02), the
risk increasing with the number of D alleles carried.
Initial ACE activity was also weakly associated with 4-week mortality
(P=.06). Values for mean initial ACE activity in those dying
by 4 weeks in each group are given in Table 4. When all
21 subjects were considered, the frequencies of the genotypes
were as follows: II, 4; ID, 8; and DD,
9, which did not differ significantly from those of survivors.
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Discussion |
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TopAbstractIntroductionSubjects and Methods Results Discussion References |
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The data from this study relate ACE genotype and plasma ACE activity in patients with stroke to the values found in a healthy community control group, free of clinically apparent cerebrovascular disease. Some of the case subjects were treated with ACE inhibitors. In most studies, chronic ACE inhibitor treatment has been associated with elevated ACE activity.20 21 In our study, 36 case subjects treated with ACE inhibitors showed significantly lower ACE activity than those not on an ACE inhibitor. Our data are in contrast with the findings of higher ACE activity in treated CAD patients6 and might have implications for the efficacy of ACE inhibitors in the primary and secondary prevention of stroke in hypertensive patients.
Levels of ACE activity were significantly lower during the acute phase of stroke but were similar to levels of control activity after 3 months. This observation is not solely due to differences in initial ACE levels between survivors and those who died, since a mean increase of 6.9 IU/L was observed in those who survived. This suggests that reduced ACE activity may be a feature of the acute event, although ACE has not previously been reported in the acute phase of cerebral infarction.22 There was no difference in ACE activity between patients with cerebral infarction and cerebral hemorrhage, which supports a nonspecific reduction in ACE activity. This view is further supported by the low levels of ACE activity in patients who died; one explanation for this is that extent of stroke is related to both mortality and depression of ACE levels. Although levels of ACE activity were lower in those with cortical strokes, this did not reach statistical significance (lower initial levels were, however, seen in subjects with PICH). Lower levels appear to be a feature of a "more severe" stroke occurring in cortical infarction and PICH as opposed to LACI.
The regulation of plasma and endothelial ACE activity is complex, with possible differences in the coronary and cerebral circulations, which may in part depend on the extent of atheroma. Furthermore, plasma ACE activity may be unrelated to intracerebral ACE activity. Although ACE has been mapped to the nigrostriatal pathway and basal ganglia,4 the role of ACE as either a direct mediator of or responder to acute cerebrovascular events is unclear. Substance P, a peptide implicated in the inflammatory response, is a substrate for ACE. Substance P has been found in intracerebral tissues and the vascular endothelium, which suggests a role in endothelial metabolism and vascular tone. ACE activity in cerebrovascular disease has not previously received much attention,23 although a recent investigation of carotid wall thickening associated increased plasma ACE activity with more elevated carotid wall thickness.24 However, it is possible that low plasma ACE activity may have preceded the acute event and be a marker for stroke risk, although this could not be validated from our data. A prospective study would be required to verify such a hypothesis. We found no evidence of age-related changes in ACE activity, although a recent study found elevated plasma ACE levels in subjects younger than 55 years with CAD.6
CAD and cerebrovascular disease share similarities in their pathophysiology. As a result, an excess of either the D allele or DD genotype in patients with stroke might have been expected, in keeping with the findings of Cambien et al8 in patients with myocardial infarction, although there is no obvious support to date for an association between the D allele and CAD (as opposed to myocardial infarction). In this population, there was no significant difference in genotype distribution between control and stroke groups, nor was any excess of the D allele observed in those with a history of stroke. We noted a deviation from the Hardy-Weinberg equilibrium among patient genotype frequencies. We could find no obvious explanation for this finding, although an association with selective survival in octogenarians has been reported with the ACE genotype.25 Our data were at variance with those of Markus et al,26 who observed an excess of the DD genotype in 18 cases of lacunar stroke. They studied a heterogeneous population of both patients with transient cerebral ischemia and patients with ischemic stroke referred for carotid duplex scanning. We used similar methods for determining lacunar syndromes, with the exception of carotid duplex scanning, and found no excess in 130 subjects with LACI.
A number of investigators have since questioned the excess of the DD genotype in subjects with CAD.27 28 Furthermore, in the prospective American Physicians Heart Study, the presence of the D allele conferred no appreciable increased risk of ischemic heart disease,29 although in a Japanese population30 and in the Caerphilly Heart Study31 an excess of the DD genotype was observed in patients with CAD. Ruiz et al32 also found a marked excess of DD genotype in non–insulin-dependent diabetes mellitus subjects with CAD. Among our subjects with a confirmed history of diabetes or CAD there was no excess of the D allele (data not shown). Contrary to previous data in subjects with essential hypertension,33 the I/D polymorphism was not associated with a history of hypertension in our subjects.
In this study ACE genotype was strongly associated with circulating ACE activity, which increased with possession of the D allele, a finding previously reported by others. We estimated that 10.7% of the variance in the initial ACE level and 14.5% at 3 months may be attributed to the I/D polymorphism, which was lower than the 22.0% of variance estimated for control subjects. This finding contrasts with the data of healthy subjects reported by Rigat et al,7 in which 47% of the variance resulted from the ACE I/D polymorphism. This suggests that factors other than the ACE I/D polymorphism are mediating ACE levels in our population.
Lower ACE activity within 10 days of the acute event was associated with a significantly increased risk of death over the following 3 months, independent of genotype. In an analysis of 4-week mortality, the risk of death rose progressively with possession of D alleles, and this association persisted when all 21 subjects were considered. From the design of this study we were unable to determine subjects who could not be included as a consequence of early death, since a local stroke register was not in place. Most deaths occurring before hospital admission are caused by PICH. It is unlikely then that the numbers of cortical infarcts were underrepresented in this study population. However, care should be taken in generalizing the findings of this hospital-based study to stroke occurring in the community.
Early stroke mortality is likely to be more directly related to the severity and extent of cerebral damage rather than the later complications of stroke such as bronchopneumonia or venous thrombosis. Although ACE activity was available in only 13 of the subjects who died within 4 weeks, early mortality was associated with lower ACE activity. The greater reduction of ACE activity in cases of PICH and TACI/PACI compared with LACI suggests a nonspecific depression related to stroke severity. Given that many of those with PICH will be due to hypertensive small-vessel disease (similar to that in LACI), we believe that this is further evidence that the fall in ACE is a nonspecific reflection of the severity of stroke. However, it is a potential pitfall for other researchers.
The results of this study demonstrate no relationship between the ACE I/D polymorphism and the development of cerebrovascular disease. Plasma ACE activity was reduced in association with acute stroke, and this was more marked in subjects with cortical infarction and PICH. A weak association was recorded between possession of the DD genotype and early mortality, as well as a trend to lower plasma ACE activity with risk of death. The mechanisms by which the D allele might act are at present speculative. It would seem likely that the relationship between ACE activity and mortality is an expression of the severity of the stroke. Prospective studies are required to evaluate this issue.
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Selected Abbreviations and Acronyms |
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Acknowledgments |
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This study and the work of the Diabetes and Thrombosis Research Group were generously supported by the Stroke Association and the Leeds General Infirmary Special Trustees.
Received June 29, 1995; revision received November 7, 1995; accepted November 27, 1995.
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References |
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TopAbstractIntroductionSubjects and Methods Results Discussion References |
|---|
1. Erdös EG, Skidgel RA. The angiotensin I-converting enzyme. Lab Invest. 1987;56:345-348. [Medline] [Order article via Infotrieve]
2. Ehlers MRW, Riordan JF. Angiotensin-converting enzyme: new concepts concerning its biological role. Biochemistry. 1989;28:5311-5316. [Medline] [Order article via Infotrieve]
3. McGeer EG, Singh EA. Angiotensin-converting enzyme in cortical tissue in Alzheimer's and some other neurological diseases. Dementia. 1992;3:299-303.
4.
Strittmatter SM, Thiele EA, Kapiloff MS, Snyder
SH. A rat brain isoenzyme of
angiotensin-converting enzyme. J
Biol Chem. 1985;260:9825-9832.
5. Alhenc-Gelas F, Richard J, Courbon D, Warnet JM, Corvol P. Distribution of plasma angiotensin I-converting enzyme levels in healthy men: relationship to environmental and hormonal parameters. J Lab Clin Med. 1991;117:33-39. [Medline] [Order article via Infotrieve]
6.
Cambien F, Costerousse O, Tiret L, Poirier O, Lecerf
L, Gonzales MF, Evans A, Arveiler D, Cambou JP, Luc G, Rakotovao R,
Ducimetiere P, Soubrier F, Alhenc-Gelas F. Plasma level and gene
polymorphism of angiotensin-converting enzyme in
relation to myocardial infarction.
Circulation. 1994;90:669-676.
7. Rigat B, Hubert C, Alhenc-Gelas F, Cambien F, Corvol P, Soubrier F. An insertion/deletion polymorphism in the angiotensin I-converting enzyme gene accounting for half the variance of serum enzyme levels. J Clin Invest. 1990;86:1343-1346.
8. Cambien F, Poirier O, Lecerf L, Evans A, Cambou JP, Arveiler D, Luc G, Bard JM, Bara L, Ricard S, Tiret L, Amouyel P, Alhenc-Gelas F, Soubrier F. Deletion polymorphism in the gene for angiotensin-converting enzyme is a potent risk factor for myocardial infarction. Nature. 1992;359:641-644. [Medline] [Order article via Infotrieve]
9. Raynolds MV, Bristow MR, Bush EW, Abraham WT, Lowes BD, Zisman LS, Taft CS, Perryman MB. Angiotensin-converting enzyme DD genotype in patients with ischaemic or idiopathic dilated cardiomyopathy. Lancet. 1993;342:1073-1075. [Medline] [Order article via Infotrieve]
10. Zingone A, Dominijanni A, Mele E, Marasco O, Melina F, Minchella P, Quaresima B, Tiano MT, Gnasso A, Pujia A, Perrotti N. Deletion polymorphism in the gene for angiotensin converting enzyme is associated with elevated fasting blood glucose levels. Hum Genet. 1994;94:207-209. [Medline] [Order article via Infotrieve]
11. Jeunemaitre X, Lifton RP, Hunt SC, Williams RR, Lalouel JM. Absence of linkage between the angiotensin converting enzyme locus and human essential hypertension. Nat Genet. 1992;1:72-75. [Medline] [Order article via Infotrieve]
12. Jacob HJ, Lindpaintner K, Lincoln SE, Kusumi K, Bunker RK, Mao YP, Ganten D, Dzau VJ, Lander ES. Genetic mapping of a gene causing hypertension in the stroke-prone spontaneously hypertensive rat. Cell. 1991;67:213-224.[Medline] [Order article via Infotrieve]
13.
Iwai N, Ohmichi N, Nakamura Y, Kinoshita M. DD
genotype of the angiotensin-converting enzyme
gene is a risk factor for left ventricular
hypertrophy. Circulation. 1994;90:2622-2628.
14.
Kupari M, Perola M, Koskinen P, Virolainen J, Karhunen
PJ. Left ventricular size, mass, and function in
relation to angiotensin-converting enzyme gene
polymorphism in humans. Am J Physiol. 1994;267:H1107-1111.
15. Hantano S. Experience from a multicentre stroke register: a preliminary report. Bull World Health Organ. 1976;54:541-553. [Medline] [Order article via Infotrieve]
16. Rose G, McCartney P, Reid DD. Self-administration of a questionnaire on chest pain and intermittent claudication. Br J Prev Soc Med.. 1977;31:42-48. [Medline] [Order article via Infotrieve]
17. Bamford J, Sandercock P, Dennis M, Burn J, Warlow C. Classification and natural history of clinically identifiable subtypes of cerebral infarction. Lancet. 1991;337:1521-1526. [Medline] [Order article via Infotrieve]
18. Gustincich S, Manfioletti G, Del Sal G, Scheinder C. A fast method for high-quality genomic DNA extraction from whole human blood. Biotechniques. 1991;11:298-301. [Medline] [Order article via Infotrieve]
19. Shanmugam V, Sell KW, Saha BK. Mistyping ACE heterozygotes. PCR Methods Appl. 1993;3:120-121. [Medline] [Order article via Infotrieve]
20. Larochelle P, Genest J, Juchel O, Bocher R, Gutkowska Y, McKinstry D. Effect of captopril (SQ14225) on blood pressure, plasma renin activity and angiotensin-I converting enzyme activity. Can Med Assoc J. 1979;121:309-316. [Abstract]
21. Sassano P, Chatellier G, Billaud E, Alhenc-Gelas F, Corvol P, Menard J. Treatment of mild to moderate hypertension with or without the converting enzyme inhibitor enalapril. Am J Med. 1988;83:227-235.
22.
Syrjanen J, Teppo AM, Valtonen VV, Iivanainen M, Maury
CP. Acute phase response in cerebral infarction.
J Clin Pathol. 1989;42:63-68.
23. Sharma P, Carter ND, Barley J, Lunt R, Seymour CA, Brown MM. Polymorphisms in the gene encoding angiotensin 1-converting enzyme and relationship to its post-translational product in cerebral infarction. J Hum Hypertens. 1994;8:633-634. [Medline] [Order article via Infotrieve]
24.
Bonithon-Kopp C, Ducimetiere P, Touboul PJ, Feve JM,
Billaud E, Courbon D, Heraud V. Plasma
angiotensin-converting enzyme activity and carotid wall
thickening. Circulation. 1994;89:952-954.
25. Schachter F, Faure-Delanef L, Guenot F, Rouger H, Froguel P, Lesueur-Ginot L, Cohen D. Genetic associations with human longevity at the APOE and ACE loci. Nat Genet. 1994;6:29-32. [Medline] [Order article via Infotrieve]
26.
Markus HS, Barley J, Lunt R, Bland JM, Jeffery S,
Carter ND, Brown MM. Angiotensin-converting
enzyme gene deletion polymorphism: a new risk factor for lacunar
stroke but not carotid atheroma. Stroke. 1995;26:1329-1333.
27. Miettinen HE, Korpela K, Hamalainen L, Kontula K. Polymorphisms of the apolipoprotein and angiotensin converting enzyme genes in young North Karelian patients with coronary heart disease. Hum Genet. 1994;94:189-192. [Medline] [Order article via Infotrieve]
28. Berge KE, Bohn M, Berg K. DNA polymorphism at the locus for angiotensinogen I-converting enzyme in Norwegian patients with myocardial infarction and controls. Clin Genet. 1994;46:102-104. [Medline] [Order article via Infotrieve]
29.
Lindpaintner K, Pfeffer MA, Kreutz R, Stampfer MJ,
Grodstein F, LaMotte F, Buring J, Hennekens CH. A prospective
evaluation of an angiotensin-converting-enzyme gene
polymorphism and the risk of ischemic heart
disease. N Engl J Med. 1995;332:706-711.
30.
Nakai K, Itoh C, Miura Y, Hotta K, Musha T, Itoh T,
Miyakawa T, Iwasaki R, Hiramori K. Deletion polymorphism of
the angiotensin I-converting enzyme gene is associated with
serum ACE concentration and increased risk for CAD in the
Japanese. Circulation. 1994;90:2199-2202.
31.
Mattu RK, Needham EWA, Galton DJ, Frangos E, Clark AJL,
Caulfield M. A DNA variant at the
angiotensin-converting enzyme gene locus associates
with coronary heart disease in the Caerphilly Heart
Study. Circulation. 1995;91:270-274.
32.
Ruiz J, Blanche H, Cohen N, Velho G, Cambien F, Cohen
D, Passa P, Froguel P. Insertion/deletion polymorphism of
the angiotensin-converting enzyme gene is strongly
associated with coronary heart disease in
non-insulin-dependent diabetes mellitus. Proc
Natl Acad Sci U S A.. 1994;91:3662-3665.
33. Zee RY, Lou YK, Griffiths LR, Morris BJ. Association of a polymorphism of the angiotensin I-converting enzyme gene with essential hypertension. Biochem Biophys Res Commun. 1992;184:9-15.[Medline] [Order article via Infotrieve]
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