Format

Send to

Choose Destination
Biol Res. 2006;39(3):403-23. Epub 2006 Nov 7.

Pituitary cell type-specific electrical activity, calcium signaling and secretion.

Author information

1
Section on Cellular Signaling, Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-4510, USA. stankos@helix.nih.gov

Abstract

All secretory anterior pituitary cells exhibit spontaneous and extracellular calcium-dependent electrical activity, but differ with respect to the patterns of firing and associated calcium signaling and hormone secretion. Thus, somatotrophs and lactotrophs fire plateau-bursting action potentials spontaneously and without coupling to calcium release from intracellular stores, which generate calcium signals of sufficient amplitude to keep steady hormone release. In these cells, both spontaneous electrical activity and basal hormone secretion can be further amplified by activation of Gq/11 and Gs-coupled receptors and inhibited by Gi/o/z-coupled receptors. In contrast, gonadotrophs fire single, high-amplitude spikes with limited ability to promote calcium influx and exocytosis, whereas activated Gq/11-coupled receptors in these cells transform single-action potential spiking into the plateau-bursting type of electrical activity and trigger periodic high-amplitude calcium signals and exocytosis of prestored secretory vesicles. Here, we review biochemical and biophysical aspects of spontaneous and receptor-controlled electrical activity, calcium signaling, and hormone secretion in pituitary cells.

PMID:
17106574
DOI:
10.4067/s0716-97602006000300004
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Scientific Electronic Library Online
Loading ...
Support Center