ANF and Head-Out Water Immersion in Normotensive and Essential Hypertensive Pregnant Women

Abstract

We studied ANF plasma and urinary cGMP concentrations before and after 30 minutes of head-out water immersion (HOWI) in 11 non pregnant normotensive women, 8 normotensive and 8 essential hypertensive pregnant women. ANF (C-terminal, Ser 99- Tyr 126) was measured by radioimmunoassay after extraction. Baseline ANF and plasma cGMP were similar in the 3 groups. Baseline urinary cGMP, cGMP clearance and urinary cGMP/ANF ratio were similar in normotensive pregnant and hypertensive pregnant women but higher in both groups than in non pregnant women (p < 0.05). HOWI induced a similar elevation in ANF plasma and urinary cGMP in the 3 groups (p < 0.05). Urinary cGMP/ANF ratio increased significantly after HOWI in the 3 groups (p < 0.05) and remained higher in pregnant women compared to non pregnant women (p < 0.05).