Centrally administered neuromedin U activates neurosecretion and induction of c-fos messenger ribonucleic acid in the paraventricular and supraoptic nuclei of rat

Endocrinology. 2002 Nov;143(11):4320-9. doi: 10.1210/en.2002-220201.

Abstract

We examined the effects of intracerebroventricular (icv) administration of neuromedin U (NMU) on plasma arginine vasopressin (AVP), oxytocin (OXT), and ACTH in rats, using RIA. The induction of c-fos protein (Fos) was examined by immunohistochemical study, and in situ hybridization histochemistry was used to detect c-fos gene expression in the paraventricular (PVN) and supraoptic nuclei (SON). Plasma AVP, OXT, and ACTH were increased in a dose-related manner 15 min after icv administration of NMU. The icv administration of NMU caused a marked induction of Fos-like immunoreactivity (LI) in the SON and the magnocellular and parvocellular divisions of the PVN. In the SON and the magnocellular divisions of the PVN, OXT-LI cells predominantly exhibited nuclear Fos-LI in comparison with AVP-LI cells. The marked induction of the expression of c-fos gene in the PVN and SON was observed 15, 30, and 60 min after icv administration of NMU. Neurosecretion and induction of c-fos gene expression after centrally administered NMU were significantly reduced by pretreatment with anti-NMU IgG. These results suggest that centrally administered NMU activates OXTergic cells in the PVN and SON predominantly as well as hypothalamo-pituitary adrenal axis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenocorticotropic Hormone / blood
  • Animals
  • Arginine Vasopressin / analysis
  • Arginine Vasopressin / blood
  • Corticosterone / blood
  • Gene Expression
  • Histocytochemistry
  • In Situ Hybridization
  • Injections, Intraventricular
  • Male
  • Neuropeptides / administration & dosage*
  • Oxytocin / analysis
  • Oxytocin / blood
  • Paraventricular Hypothalamic Nucleus / chemistry
  • Paraventricular Hypothalamic Nucleus / metabolism*
  • Proto-Oncogene Proteins c-fos / analysis
  • Proto-Oncogene Proteins c-fos / biosynthesis
  • Proto-Oncogene Proteins c-fos / genetics*
  • RNA, Messenger / biosynthesis*
  • Rats
  • Rats, Wistar
  • Supraoptic Nucleus / chemistry
  • Supraoptic Nucleus / metabolism*

Substances

  • Neuropeptides
  • Proto-Oncogene Proteins c-fos
  • RNA, Messenger
  • Arginine Vasopressin
  • neuromedin U
  • Oxytocin
  • Adrenocorticotropic Hormone
  • Corticosterone