Digoxin-like immunoreactivity, displacement of ouabain and inhibition of Na+/K+ ATPase by four steroids known to be increased in essential hypertension.

An endogenous digoxin-like immunoreactive substance(s) (DLIS, "endoxin") may be of significance in the etiology of essential hypertension (EH). Progesterone, dehydroepiandrosterone sulphate (DHEA-S), 11-deoxycortisol and 18-hydroxy-11-deoxycorticosterone (18-OH-DOC), four steroids known to be increased in essential hypertension, were found to have digoxin-like immunoreactivity at levels 1,000 times higher than physiological concentrations. Of these steroids, progesterone and 18-OH-DOC were the most efficient in displacing 3H-ouabain from canine kidney Na+/K+ ATPase whereas progesterone and 11-deoxycortisol were the most potent inhibitors of this enzyme's activity.

Plasma cortisol and corticosteroid-binding globulin in essential hypertension.

Plasma concentration of cortisol, total CBG-binding capacity, and blood pressure were measured in control subjects (n = 171), patients with essential hypertension (EH; n = 210) and their first-degree normotensive (NR; n = 84) or hypertensive (HR; n = 66) relatives. Mean (+/- SD) plasma cortisol was significantly (p less than 0.001) decreased in EH (10.

The relationship of plasma aldosterone-binding globulin to blood pressure regulation in young adults with cystic fibrosis.

Findings of increased secretion rate and decreased metabolic clearance rate (MCR) of aldosterone in patients with cystic fibrosis of the pancreas (CF) and our own evidence on the association of increased aldosterone-binding globulin (ABG)-binding and decreased MCR in essential hypertension (EH) inspired us to investigate the plasma aldosterone, with the inclusion of protein-binding variables, in CF patients. (1) The percentage of plasma aldosterone specifically bound to ABG was measured in 55 young adults with CF in addition to total plasma aldosterone, total plasma corticosteroids and for comparison of corticosteroid-binding globulin (CBG)-binding capacity. (2) The percentage of ABG-bound plasma aldosterone was found to vary with the seasonal change in temperature and the hepatic function of CF patients.

Renin angiotensin aldosterone axis, including aldosterone binding globulin and blood pressure in three species of nonhuman primates.

Variables of renin-angiotensin-aldosterone axis with inclusion of protein binding to specific plasma globulin (ABG), plasma cortisol, and the blood pressure (BP) were measured in 24 chimpanzees, 4 gorillas, and 16 cynomolgus monkeys. ABG activity was readily detected in plasma from the primates. In chimpanzees and gorillas, all the variables under baseline conditions were similar to those in humans.

Absence of plasma protein binding of aldosterone in normal and estrogen-treated rabbit.

In experiments on direct effects of prolonged administration of estrogen on In experiments on direct effects of prolonged administration of estrogen on mean arterial pressure (MAP) and plasma corticosteroid-binding variables in the rabbit the following observations were made. Estrogen had no effect on MAP but resulted in a nonsignificant stimulation of total plasma corticosteroids and a marked increase in corticosteroid-binding globulin (CBG) binding capacity which increased from a control value of 18.8 +/- (SD) 1.