Regulation of galanin-like peptide gene expression by pituitary hormones and their downstream targets

M. J. Cunningham, S. M. Krasnow, E. F. Gevers, P. Chen, C. K. Thompson, I. C.A.F. Robinson, M. S. Smith, D. K. Clifton, Robert A. Steiner

Research output: Contribution to journalArticle

30 Scopus citations

Abstract

Galanin-like peptide (GALP) mRNA is expressed in neurones of the hypothalamic arcuate nucleus and within pituicytes in the neurohypophysis. Several neuropeptides that are expressed in the arcuate nucleus participate in the neuroendocrine regulation of pituitary hormone secretion. Our objective was to determine the extent to which GALP might be a target for regulation by pituitary hormones or their downstream targets in the rat. The expression of GALP mRNA in the arcuate nucleus was reduced by hypophysectomy as determined by in situ hybridization. However, this did not appear to be attributable to the loss of either gonadal or adrenal steroids because castrated, ovariectomized and adrenalectomized rats had GALP mRNA expression that was indistinguishable from their respective controls. Next, we investigated the effects of growth hormone deficiency on GALP mRNA expression by studying dwarf rats and found that GALP gene expression was not different between dwarf rats and controls. We found that thyroidectomy led to a significant reduction in GALP mRNA expression compared to intact controls, and thyroidectomized rats implanted with thyroxine pellets had GALP mRNA expression that was similar to intact controls. Thus, the reduction of GALP mRNA expression seen in hypophysectomized animals may reflect, in part, a selective loss of thyroid hormone. We also found that the expression of GALP mRNA was increased in the neurohypophysis of lactating rats compared to nonlactating rats, whereas GALP mRNA expression in the arcuate nucleus was unaffected by lactation. This suggests that the induction of GALP gene expression in pituicytes is physiologically associated with activation of oxytocin and vasopressin secretion during lactation.

Original languageEnglish (US)
Pages (from-to)10-18
Number of pages9
JournalJournal of Neuroendocrinology
Volume16
Issue number1
DOIs
StatePublished - Jan 1 2004

Keywords

  • Arcuate nucleus
  • Hypophysectomy
  • Lactation
  • Neurohypophysis
  • Thyroidectomy
  • in situ hybridization

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology
  • Endocrine and Autonomic Systems
  • Cellular and Molecular Neuroscience

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    Cunningham, M. J., Krasnow, S. M., Gevers, E. F., Chen, P., Thompson, C. K., Robinson, I. C. A. F., Smith, M. S., Clifton, D. K., & Steiner, R. A. (2004). Regulation of galanin-like peptide gene expression by pituitary hormones and their downstream targets. Journal of Neuroendocrinology, 16(1), 10-18. https://doi.org/10.1111/j.1365-2826.2004.01118.x