Oneliner_1960

OneLiner

Lisinopril is an inhibitor of angiotensin-converting enzyme (ACE), which cleaves angiotensin I to form angiotensin II. Angiotensin II acts on vascular smooth muscle cells causing them to contract. In the efferent renal arteriole cells, this contraction increases the glomerular filtration rate (see image). Angiotensin II works, in this case, by binding to angiotensin receptor type I, which is a seven-transmembrane domain receptor coupled with a G protein (Gq) that activates phospholipase C. Phospholipase C cleaves phosphatidylinositol (4,5)-bisphosphonate (PIP2) to form inositol phosphate 3 (IP3) and diacylglycerol (DAG). IP3 opens calcium channels, causing an intracellular increase in calcium, and DAG activates protein kinase C. Thus an ACE inhibitor, like lisinopril, will cause decreased activation of Gq and decreased activity of phospholipase C in vascular smooth muscle cells.