Relationship between leucocyte sodium content and high blood pressure during development and resolution of pre-eclampsia.

1. One hundred and five primigravidae were followed sequentially at 4-weekly intervals starting at gestational week 31. They were seen again at 6 weeks post partum. 2. At each visit measurements were made of blood pressure as well as of leucocyte and erythrocyte sodium and potassium content. 3. Eighty-five subjects completed the study. Seven developed pre-eclampsia. 4. In both controls and patients who developed pre-eclampsia, leucocyte and erythrocyte sodium content increased with gestational age and fell post partum. These changes were of greater magnitude in the patients with pre-eclampsia. Cell potassium fell in both groups, but to a greater extent in patients with pre-eclampsia. 5. These changes in cell sodium paralleled those in blood pressure in both groups. 6. These data suggest that the excessive blood pressure changes in pre-eclampsia might be related to similar changes in cell sodium content.