The relevance of the interaction between sodium and rennin–angiotensin balance in malignantHT is revealed by a study made on a group of subjects with renal dysfunction and accelerated HT.Lowering the BP values after the administration of ACE inhibitors is abruptly altered after theinfusion of saline solution, with the establishing of a positive Na balance and the reduced plasmarennin concentration. Here, ACE is linked to hematocrit.