 In the opposite case, juxtaglomerular cells are stimulated to release more renin, which stimulates the renin–angiotensin system, producing angiotensin I which is converted by Angio-Tensin Converting Enzyme (ACE) to angiotensin II.Angiotensin II then causes preferential constriction of the efferent arteriole of the glomerulus and increases the GFR.This is so-called "steady-state system".