POTENTIATION OF ACTH HYPERTENSION IN MAN WITH SALT LOADING

ACTH 1 mg/day for 5 days raises systolic blood pressure (SBP) in normotensive and hypertensive subjects on a fixed electrolyte intake of 100 mmol/day sodium (Na) and potassium (K) (Whitworth et al. 1983). The present study examined the effect of Na intake in the high normal range on the haemodynamic and metabolic responses to ACTH. ACTH administration on a 200-300 mmol Na intake increased SBP by 35 mmHg (s.e.m. = 11, n = 5) compared with the 22 mmHg (s.e.m. = 4, n = 12) rise seen on a 100 mmol Na intake in our previous study. These studies suggest that the effects of adrenocortical steroids on blood pressure in man may be magnified by increasing dietary Na intake.