Influence of gender and genetic variability on plasma angiotensin peptides.

INTRODUCTION: We analysed the influence of three polymorphisms of the renin-angiotensin system (RAS) (I/D from angiotensin-converting enzyme [ACE], M235T from angiotensinogen gene [ATG] and A1166C from AT1 receptors) on plasma levels of angiotensin I (Ang I), angiotensin II (Ang II) and angiotensin-(1-7) [Ang-(1-7)]. MATERIALS AND METHODS: The study population consisted of a homogeneous group of 93 healthy subjects (43 men and 50 women, mean age: 20.67+/-2.75 years). The mean blood pressure (BP) was 126+/-7/76+/-5 (SD) mmHg and the mean body mass index (BMI) was 22.4+/-2.5 kg/m2. Angiotensin peptides were separated by high performance liquid chromatography (HPLC) and quantified by radio immuno assay (RIA). Genotypes were determined by polymerase chain reaction (PCR) and restriction enzyme analysis. RESULTS: Mean peptide levels were 92.48+/-102.12 pg/ml for Ang I, 22.35+/-10 pg/ml for Ang II, and 31.65+/-27.46 pg/ml for Ang-(1-7). Men had significantly higher levels of Ang-(1-7) (37.76+/-36.47 pg/ml) than women (26.04+/-13.98 pg/ml) (p<0.05). Among genotypes of each polymorphism, men with the T allele showed higher Ang- (1-7) levels compared with those with the MM genotype (p<0.05). Genotype analysis in women showed that higher Ang I levels were related with the DD genotype. When both genders were compared according to genotype, higher values of Ang-(1-7) levels and its molar ratios were found in men, and there was significantly greater Ang I levels in DD genotypes in women than men (136.72+/-112.43 vs . 65.36+/-46.83 pg/mL). CONCLUSIONS: Significant correlations were found between Ang I and Ang II as well as between Ang II and Ang-(1-7) in the different study group distributions. No correlation was found between levels of Ang I and Ang-(1-7). Certain genotypes exert an influence on angiotensin peptide plasma levels which can only be seen when the population is divided according to gender.