Why are endocrine pituitary cells excitable?
Since 1975, endocrine pituitary cells have been known to be excitable neuronlike cells. Using powerful single-cell approaches, in particular the patch clamp electrophysiological recording technique and the monitoring of Ca(2+) with fluorescent probes, solid evidence has been provided in the last 10 years that intracellular Ca(2+) signals are produced by stimulators and inhibitors of secretion via the modulation of action potentials in isolated pituitary cells. As cytosolic Ca(2+) changes are thought to control numerous cellular functions (for example, secretion, protein synthesis, gene expression, and proliferation) over a long time scale-milliseconds to hours-it is now time to address the long-standing question of what functions would be physiologically controlled by electrical excitability in intact pituitary tissue.
Mollard
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Patrice Mollard is at INSERM Unité 401, Pharmacologie Moléculaire de Récepteurs d'Hormones Peptidiques, CCIPE, 141 Rue de la Cardonille, 34094 Montpellier, Cedex 05 France.
Schlegel
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