Neuroendocrine plasticity in the anterior pituitary: gonadotropin-releasing hormone-mediated movement in vitro and in vivo

Endocrinology. 2007 Apr;148(4):1736-44. doi: 10.1210/en.2006-1153. Epub 2007 Jan 11.

Abstract

The secretion of LH is cued by the hypothalamic neuropeptide, GnRH. After delivery to the anterior pituitary gland via the hypothalamic-pituitary portal vasculature, GnRH binds to specific high-affinity receptors on the surface of gonadotrope cells and stimulates synthesis and secretion of the gonadotropins, FSH, and LH. In the current study, GnRH caused acute and dramatic changes in cellular morphology in the gonadotrope-derived alphaT3-1 cell line, which appeared to be mediated by engagement of the actin cytoskeleton; disruption of actin with jasplakinolide abrogated cell movement and GnRH-induced activation of ERK. In live murine pituitary slices infected with an adenovirus-containing Rous sarcoma virus-green fluorescent protein, selected cells responded to GnRH by altering their cellular movements characterized by both formation and extension of cell processes and, surprisingly, spatial repositioning. Consistent with the latter observation, GnRH stimulation increased the migration of dissociated pituitary cells in transwell chambers. Our data using live pituitary slices are a striking example of neuropeptide-evoked movements of cells outside the central nervous system and in a mature peripheral endocrine organ. These findings call for a fundamental change in the current dogma of simple passive diffusion of LH from gonadotropes to capillaries in the pituitary gland.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cell Movement / drug effects*
  • Cells, Cultured
  • Cytoskeleton / drug effects
  • Gonadotropin-Releasing Hormone / metabolism
  • Gonadotropin-Releasing Hormone / pharmacology*
  • Mice
  • Microscopy, Video
  • Neuronal Plasticity* / drug effects
  • Neurosecretory Systems / drug effects
  • Neurosecretory Systems / physiology*
  • Organ Culture Techniques
  • Pituitary Gland, Anterior / cytology*
  • Pituitary Gland, Anterior / drug effects
  • Sheep

Substances

  • Gonadotropin-Releasing Hormone