Pharmacological activity of angiotensin-II modified by tyrosine sulfation

An angiotensin-II analogue with a sulfated tyrosine residue was prepared by arylsulfotransferase treatment of synthetic human angiotensin-II. Its biological activities were studied in isolated smooth muscles, and its effect on blood pressure was determined. The sulfated angiotensin-II (AII-S) was about 15-30 fold less potent than angiotensin-II (AII) for ileum contraction and gallbladder contraction. The hypertensive potency of AII-S was about 30-fold less than that of AII.