Estimation of Circulating Renin in Normal and Toxemic Pregnancy.

Toxemia of pregnancy is a symptom complex which occurs during pregnancy and consists of three essential manifestations; hypertension, proteinuria and edema. Although extensive attempts have been made to explain the genesis of toxemia, none is satisfactory to date. Recently it has been assumed that a humoral substance is liberated and changes the metabolism of the gravids. Hunter and Howard1) reported that there occurred a pressor substance, named "histerotonin", in the placenta and the plasma of toxemic patients, which caused hypertension. On the other hand, many investigators2-7) observed that the excretion and the secretion of aldosterone were increased in pregnancy. In recent years, it has been made clear that the factor regulating excretion and/or secretion of aldosterone is renin-angiotensin systems8,9). In the earlier papers10,11) from this laboratory on the assay of circulating ren in, it was reported that plasma renin was elevated in patients with secondary aldosteronism and in normal subjects under salt deprivation, a condition known to