Expression of Angiotensin II Subtype 1a Receptor (AT1a) During Pregnancy in Mouse

Abstract

ObjectiveThe AT1a receptor plays an important role in blood pressure regulation during pregnancy but its expression in gestation is not well defined. There is also significant interaction between AT1a and angiotensin II subtype 2 receptors (AT2). Therefore, we examined AT1a expression in wild type(WT) and AT2 knockout mice (AT2(−/−)) throughout pregnancy to determine the pattern of expression and if the AT2 receptor influences any pregnancy‐related changes.MethodsSix mice from each group were sacrificed in early‐, mid‐ and late gestation. Tissues such as kidney and placenta were collected. Western blot was used to examine the expression of the receptor. ANOVA followed with Newman‐Keuls test was used to analyze data from kidney, t test was used to analyze data from placenta.ResultsIn placenta, compared to mid gestation, AT1a decreased in late gestation in WT mice (0.63±0.13 vs. 0.27±0.07*) but not in AT2(−/−) mice (0.77±0.17 vs. 0.75±0.07). Similarly, in kidney, compared to early gestation, AT1a was lower in mid‐ and late gestation in WT mice (1.16±0.03, 0.91± 0.12*, 0.81±0.05*) but not in AT2(−/−) mice (0.79±0.05, 0.66±0.05, 0.78±0.12).ConclusionExpression of the AT1a decreases during pregnancy in placenta and kidney in normal but not in AT2(−/−) mice. AT2 receptors might play an important role in AT1 expression variation during pregnancy in mice.