Differential hypothalamic neuronal activation following peripheral injection of GLP-1 and oxyntomodulin in mice detected by manganese-enhanced magnetic resonance imaging

Biochem Biophys Res Commun. 2006 Nov 17;350(2):298-306. doi: 10.1016/j.bbrc.2006.09.033. Epub 2006 Sep 18.

Abstract

The anorexigenic gut hormones oxyntomodulin (OXM) and glucagon-like peptide-1 (GLP-1) are thought to physiologically regulate appetite and food intake. Using manganese-enhanced magnetic resonance imaging, we have shown distinct patterns of neuronal activation in the hypothalamus in response to intraperitoneal injections into fasted mice of 900 and 5400 nmol/kg OXM or 900 nmol/kg GLP-1. Administration of OXM at either dose resulted in a reduced rate of signal enhancement, reflecting a reduction in neuronal activity, in the arcuate, paraventricular, and supraoptic nuclei of the hypothalamus. Conversely, GLP-1 caused a reduction in signal enhancement in the paraventricular nucleus only and an increase in the ventromedial hypothalamic nucleus. Our data show that these two apparently similar peptides generate distinct patterns of activation within the hypothalamus, suggesting that GLP-1 and OXM may act via different hypothalamic pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Eating* / drug effects
  • Fasting
  • Glucagon-Like Peptide 1 / administration & dosage
  • Glucagon-Like Peptide 1 / pharmacology*
  • Hypothalamus / anatomy & histology
  • Hypothalamus / cytology
  • Hypothalamus / physiology*
  • Injections
  • Injections, Intraperitoneal
  • Kinetics
  • Magnetic Resonance Imaging / methods
  • Male
  • Manganese / analysis
  • Mice
  • Mice, Inbred C57BL
  • Neurons / drug effects
  • Neurons / physiology*
  • Oxyntomodulin / administration & dosage
  • Oxyntomodulin / pharmacology*
  • Peptide Fragments / administration & dosage
  • Peptide Fragments / pharmacology*

Substances

  • Oxyntomodulin
  • Peptide Fragments
  • glucagon-like peptide 1 (7-36)amide
  • Manganese
  • Glucagon-Like Peptide 1