The active form of angiotensin. An octapeptide found in blood, it is synthesized from ANGIOTENSIN I and quickly destroyed. Angiotensin II causes profound
vasoconstriction with a resulting increase in
blood pressure. It differs among species by the amino acid in position 5. The human form has
isoleucine in this position. The clinically and experimentally used bovine form has
valine in position 5. Medically useful antagonism is obtained with ACE INHIBITORS or with
angiotensin ii type 1 receptor blockers.