The importance of angiotensin II subtype receptors for blood pressure control during mouse pregnancy.

Pregnancy is characterized by a progressive increase in the different components of the renin angiotensin system (RAS) including angiotensin II, a potent vasoconstrictor. Pregnant women and experimental animals are resistant to the pressor effect of increased angiotensin II concentrations during pregnancy. In normal pregnancy, maternal blood pressure (BP) begins to fall in early gestation, reaches a nadir in midgestation, and then gradually increases to nonpregnant levels before term in both humans and C57BL/6J mice.