The Effect of Angiotensin II Type-1 Receptor Gene Polymorphisms on Doppler Blood Flow Parameters of Carotid and Brachial Arteries in Patients with Myocardial Infarction

Association between angiotensin II type-1 receptor A1166C polymorphism and the presence of angiographically-defined coronary artery disease in an Iranian population

Background: There are reported associations between a polymorphism of the angiotensin II type 1 receptor (AT1R/A1166C) gene and coronary artery disease (CAD), hypertension, and myocardial infarction in some populations. Objective: Investigate the association between A1166C polymorphism and CAD in an Iranian population. Methods: Four hundred and thirteen patients with suspected CAD were recruited. Based on coronary angiography, the patients were classified into CAD+ (n=315) and CAD- (n=98) groups defined as >50% and <50% stenosis of any major coronary artery, respectively. One hundred and thirty-five healthy subjects were also recruited as the control group. The AT1R polymorphism was assessed using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) based method. Results: A higher frequency of the AC and CC genotypes and lower frequency of the AA genotype was observed in both CAD+ and CAD- groups, compared with the control group (p <0.05). CAD+ and CAD- groups also had a higher frequency of the C allele than controls (p <0.01). There was no significant difference in genotype and allele frequencies between hypertensive and non-hypertensive patients (p > 0.05). In addition, the AT1R genotype frequencies did not differ significantly among different subgroups of CAD+ patients, based on the number of affected coronary vessels (p >0.05). Conclusion: The frequency AT1R/A1166C polymorphism was higher among patients with some degrees of coronary stenosis who are candidates of coronary angiography.

The Relationship between Angiotensin-II Type 1 Receptor Gene Polymorphism and Repolarization Parameters after a First Anterior Acute Myocardial Infarction

Background and Objectives

Genetic influence on T-wave peak to End (Tpe) time in patients with a first anterior acute myocardial infarction (AMI) is uncertain. A polymorphism in the angiotensin-II type 1 receptor (AT1R) gene was discovered recently. The polymorphism consists of an A or C variant, given three different possible genotypes: AA, AC, CC. The purpose of this study was to determine the effects of polymorphism of the AT1R gene polymorphism on Tpe after a first anterior AMI.

Subjects and Methods

The subjects were 142 patients (110 men, 32 women, 58±13 years) with a first anterior AMI; ten patients were excluded from this study. Based on the polymorphism of the AT1R gene, they were classified into two groups: Group 1 (AA genotype) of 91 patients and group 2 (AC and CC genotype) of 41 patients. A 12-lead resting ECG was recorded at admission to the coronary care unit in patients with anterior AMI and were manually measured with a ruler. QTc, QTd, QTcd, Tpe, Tpe/QT parameters were measured.

Results

There was no significant difference in the baseline characteristics of patients (p>0.05). We found significant reduction in QTc, QTd, QTcd, Tpe, Tpe/QT indices Group 1 (AA genotype) (mean 66±28 ms) than group 2 (AC and CC genotype) (mean 95±34 ms) (p<0.05).

Conclusion

In patients with a first anterior AMI, AT1R gene polymorphisms may influence on repolarization parameters. Although further studies are required.

XRCC1 399 Arg-related genotype and allele, but not XRCC1 His107Arg, XRCC1 Trp194Arg, KCNQ2, AT1R, and hOGG1 polymorphisms, are associated with higher susceptibility of endometriosis

X-ray repair cross-complementing group 1 (XRCC1) and human 8-oxoguanine glycosylase 1 (hOGG1) play important roles in base excision repair. KCNQ genes comprising voltage-gated ion-channels related with cell stability. Angiotensin II type 1 receptor (AT1R) is related with angiogenesis, which influence endometriosis growth, invasion and regression. We aimed to investigate whether these polymorphisms were associated with endometriosis susceptibility. Women were divided [ 1 ]: endometriosis (n = 136 [ 2 ]); non-endometriosis groups (n = 112). XRCC1 (codon 107, 194, 399), hOGG1, KCNQ2, AT1R polymorphisms were amplified by PCR and detected by electrophoresis after restriction enzyme (RsaI, HpaII, MspI, Fnu4HI, Ava II, Dde I) digestions. Genotypes and allelic frequencies in both groups were compared. Proportions of XRCC1 Arg399Gln*GG/GA/AA and G/A allele between both groups were [ 1 ]: 41.9/53.7/4.4% and 68.8/31.2% [ 2 ]; 30.4/54.5/15.1% and 57.6/42.4% (p < 0.05). Other 5 polymorphisms (XRCC1 codon 107 and 194, hOGG1, KCNQ2, and AT1R) between both groups were non-significantly different. Proportions of XRCC1 107*AA/AG/GG and XRCC1 194*TT/TC/CC between both groups were [ 1 ]: 3.7/27.2/69.1% and 5.8/34.6/59.6% [ 2 ]; 2.6/21.4/75.8% and 11.6/37.5/50.9%. HOGG1*CC/CG/GG, KCNQ2*AA/AC/CCC and AT1R*AA/AC/CC were [ 1 ]: 14.8/42.6/42.6, 14/41.9/44.1 and 92.6/7.4/0% [ 2 ]; 11.6/50/38.4, 17/50/33 and 100/0/0%. We concluded that XRCC1 399 Arg-related genotype and allele are correlated with higher susceptibility to endometriosis, which suggested its association with endometriosis pathogenesis. XRCC1 107 and 194, hOGG1, KCNQ2, and AT1R are not associated with endometriosis susceptibility.