The isolation of hypertensin from the circulating blood of normal dogs with experimental renal hypertension by dialysis in an artificial kidney.

T HE PRESENT paper is a report on experimental procedures designed to determine whether hypertensin is the vasoconstrictor substance responsible for the elevation of blood pressure in. dogs with benign experimental renal hypertension. Previous work' has shown that a pressor material similar in all general respects to hypertensin can be dialyzed out of the circulating blood of dogs by the use of an artificial kidney.2 The pressor material was present in the dialyzates of dogs under the following experimental conditions: (1) 4 dogs with malignant hypertension; (2) 2 out of 9 normal animals; (3) 2 normal dogs in which the artificial kidney was filled with blood from donor dogs which were not nephrectomized; and (4) 3 out of 9 dogswhichwere injected intravenously with varying amounts of renin. The dialyzates from the dogs were worked up chemically and then injected intravenously into rats to determine the amount and kind of pressor material that was present. The rat was chosen as the test animal because it was found that 0.01 of a Goldblatt unit of hypertensin3