CALCIUM SIGNALING AND SECRETION IN PITUITARY-CELLS

An important trigger of hormone secretion from pituitary cells is a ri se in cytosolic Ca2+ ([Ca2+](i)). Pituitary cells may modulate [Ca2+]( i) by an increased membrane flux from the extracellular space and/or b y a release from intracellular stores. Both mechanisms can support exo cytosis, although in different pituitary cell types one or the other m echanism may predominate. Molecular events transducing a rise in [Ca2](i) into hormone secretion are still poorly understood. Here, the exo cytotic machinery in pituitary cells is briefly reviewed in terms of t he spatial organization of [Ca2+](i) elevation relative to the Ca2+ se nsor(s). (C) 1996, Elsevier Science Inc.