Alu insertion/deletion of ACE gene polymorphism might not affect significantly the serum bradykinin level in hypertensive patients taking ACE inhibitors

Abstract

Background: Angiotensin I-converting enzyme (ACE) has two homologous catalytic domains, the N- and C-domains. Our previous study suggested that Alu insertion (I allele) in the intron 16 of ACE resulted in premature codon termination. The I allele has only one active site in the Ndomain while the Alu deletion (D allele) still has two active sites of ACE. Therefore the effect of I/ D polymorphism of ACE on the enzyme’s ability to catalyse bradykinin is still not widely known.
Aims: This study aimed to examine the serum bradykinin level in hypertensive patients with I/D polymorphism of ACE, who were treated with ACE inhibitor.
Subjects and methods: The serum bradykinin and I/D polymorphism have been detected in 64 hypertensive patients taking ACE inhibitor (lisinopril or captopril) for at least eight weeks with good medication adherence. The binding affinity ofACEwith its receptor was calculated by molecular docking.
Results: The findings show that genotype II is more frequent in the population the researchers observed (53.12%) compared to ID (23.44%) andDD(23.44%) variances.Onthe other hand, the bradykinin level is not affected by genotype of the ACE genes on the population. Bradykinin increases in patients with genotype II who are given captopril, but decreases in patients treated with lisinopril. Nevertheless, there is no statistically significant difference.
Conclusion: This study suggests that the polymorphism might not significantly affect the serum bradykinin level in hypertensive patients taking ACE inhibitors.