Selective increase in placental blood flow by atrial natriuretic peptide in hypertensive rats.

Effects of atrial natriuretic peptide on systemic, renal, uterine, and placental hemodynamics were determined in 16-day pregnant normotensive and hypertensive rats and in 20-day pregnant normotensive rats under pentobarbital anesthesia. Relative to 16-day pregnant normotensive rats, the total peripheral resistance was higher in 16-day pregnant hypertensive and 20-day pregnant normotensive rats; atrial natriuretic peptide significantly (p less than 0.05) decreased the total peripheral resistance in the latter two groups of animals. Atrial natriuretic peptide increased the placental blood flow in each of the three groups of animals without significantly affecting renal blood flow. This selective increase in placental blood flow normalized placental hemodynamics in hypertensive rats.