1. The chemical mediator of renal hypertension is rapidly destroyed by the metabolic activity of the normal kidney. The excretory function of the kidney plays little, if any, rôle in eliminating the mediator of hypertension.
2. If specific substances are responsible for the uremic syndrome, they are neither produced nor eliminated to any significant extent by the metabolic activity of the kidneys. The elimination of these postulated uremia-producing substances would have to be primarily dependent upon the excretory activities of the kidney.
3. No evidence was obtained to support the view that a unilateral ureterovenous fistula leads to "nephrotoxic" symptoms.