Absence of an acute effect of calcium or parathyroid hormone administration on plasma renin activity in man.

1. There was no significant change in plasma renin activity over 6 h in five subjects given calcium gluconate or in four subjects given parathyroid hormone. 2. It is concluded that acute hypercalcaemia does not increase plasma renin activity and is unlikely to play a role in the hypertension found with primary hyperparathyroidism.