Changes in population density elicit quantitative and qualitative changes in the estrogen receptor in intact GH4C1 pituitary tumor cells

Anterior pituitary cells: getting to know their neighbors

We review in this article recent findings on the effects of cell proximity (nearness to each other) on anterior pituitary cell function in vitro. Important cellular processes, including protein synthesis, basal hormone release, response to hypothalamic regulatory factors and signal transduction can change as a function of the distance between adjacent cells. These findings, together with a growing body of evidence on intrapituitary intercellular interactions, form a basis for proposing a model of anterior pituitary cell regulation. In this scheme extrapituitary, intracellular and intercellular signaling pathways all contribute and interact to control secretory processes in cells.