Description
Angiotensin II (AT II) is a peptide produced from AT I by angiotensin-converting-enzyme (ACE). AT II binds the AT II type 1 (AT1) receptor, stimulating GPCRs in vascular smooth muscle cells and increasing intracellular Ca2+ levels; this results in contraction and vasoconstriction, increasing blood pressure. AT II also acts at the Na+/H+ exchanger in the proximal tubules of the kidney. Here, AT II increases reabsorption of Na+ and HCO3- and excretion of H+, increasing blood volume and pH and further increasing blood pressure.