T he renin-angiotensin system (RAS) is considered to be a circulating peptidergic system with mainly endocrine characteristics. ''Local RAS'' components [renin, angiotensin converting enzyme (ACE), and angiotensinogen] are present in most of the major organs of the female reproductive tract, including the uterus, ovary, and placenta, and have independent autocrine-paracrine actions. They mediate critical pathobiologic events, such as angiogenesis, cellular growth, signal transduction, local vascular endothelial functions, apoptosis, and many others, independent of the circulating systems. Previously, the authors demonstrated a local RAS in human umbilical cord by verifying the corresponding ACE, renin, and angiotensinogen mRNAs. In this study, they investigated alterations of the local umbilical cord RAS during preeclampsia versus normal pregnancy, hypothesizing that identification and proper modification of cord RAS could open new opportunities in the management of this disorder.Cord blood samples were obtained from 19 parturients with preeclampsia [mean age 26.60 ± 5.83 y (range, 18 to 42)] and 20 women with normal pregnancy [controls; 28.26 ± 7.30 y (19 to 37)] using tubes with ethylenediaminetetraacetate. Infants with intrauterine growth restriction were identified in 10 women with preeclampsia; all other infants were classified as appropriate for gestational age. Real-time quantitative polymerase chain reaction analysis for ACE, renin, and angiotensinogen gene expressions were carried out using the LightCycler instrument and results were analyzed by LC software 3.0.Specific mRNAs for all three components of the RAS were detected in cord blood samples by polymerase chain reaction analysis. Among controls, the mean expression ratios were 0.0029 ± 0.0015 for renin, 0.153 ± 0.166 for angiotensinogen, and 0.220 ± 0.294 for ACE. Renin expressions were significantly higher in preeclamptic women. In preeclamptic women, the mean expression ratios were 0.0061 ± 0.00068 for renin (P<0.05), 0.035 ± 0.008 for angiotensinogen (P<0.05), and 0.030 ± 0.0006 for ACE genes (P<0.05). However, there were no significant differences in mean expression ratios of renin, angiotensinogen, and ACE genes between intrauterine growth restriction and appropriate for gestational age newborns.
