Some hormone studies in normal and toxemic pregnancy.

The steroids of the adrenal cortex assist in, and are necessary for, normal excretion of water and electrolyte (1). In general, these steroids tend to cause water excretion and salt retention, the relative amounts of these responses being dependent upon the structure of the steroid. The hormones of the posterior pituitary gland, on the other hand, cause water retention and, usually, sodium and chloride excretion (1). A reciprocal relationship between these hormones has been proposed (2). Since the suggestion by Hofbauer (3) on theoretical grounds that posterior pituitary hormones might play a part in the development of eclampsia and the report by Anselmino, Hoffmann, and Kennedy (4) of an increased level of an antidiuretic material in the plasma of toxemic patients, a large number of studies of the role of antidiuretic materials in toxemia have been carried out. Some of these studies have failed to demonstrate an antidiuretic substance or have failed to show a correlation between antidiuretic activity and toxemia of late pregnancy. The failures to find increased antidiuretic activity have been mostly when antidiuretic activity has been sought in serum or plasma (5-10). A good many workers have been able to show an increased urinary antidiuretic activity (11-13) or an increased sensitivity to exogenous posterior pituitary hormone in patients with pre-eclampsia or eclampsia (10, 14-17). Several studies of corticosteroid excretion during pregnancy have found the level of these steroids, to be increased in toxemia (18-21). It has recently been demonstrated in normal non-pregnant subjects and in patients with abnormalities of water excretion that during a state of positive water balance, a relatively high level of antidiuretic activity in serum and a relatively low urinary cor-