Endothelin Action on Pituitary Lactotrophs: One Receptor, Many GTP-Binding Proteins

R. Bertram, J. Tabak, N. Toporikova, M. E. Freeman

The endothelins are a family of hormones that have a biphasic action on pituitary lactotrophs. The initial effect is stimulatory, followed later by inhibition that persists long after the agonist has been followed later by inhibition that persists long after the agonist has been removed. Recent research has uncovered the several G protein pathways that mediate these effects. We describe the different pathways.