Introduction The kidneys are also involved in promoting erythropoiesis and producing activated vitamin D erythropoiesis (red blood cell production) the kidneys produce a glycoprotein growth factor called erythropoietin (EPO) login to view 5 more bullets vitamin D production the kidneys contain an enzyme called 1α-hydroxylase login to view 10 more bullets Prostaglandins the kidneys locally produce prostaglandins (e.g., PGE2) that result in vasodilation of the afferent arteriole this in turn increases renal blood flow nonsteroidal antiinflammatory drugs (NSAIDs) impair prostaglandin synthesis login to view 1 more bullet Dopamine low levels of dopamine dilates the renal arterioles and thus increases renal blood flow secreted by proximal tubular cells to promote natriuresis