Angiotensin II (5-8), human is an endogenous C-terminal fragment of the peptide vasoconstrictor angiotensin II. Angiotensin II binds the AT II type 1 (AT1) receptor, stimulating GPCRs in vascular smooth muscle cells and increasing intracellular Ca2+ levels. Angiotensin II also acts at the Na+/H+ exchanger in the proximal tubules of the kidney.