Glycyl-l-glutamine attenuates NPY-induced hyperphagia via the melanocortin system

Neurosci Lett. 2020 Sep 25:736:135303. doi: 10.1016/j.neulet.2020.135303. Epub 2020 Aug 12.

Abstract

This study aimed to determine whether glycyl-l-glutamine (Gly-Gln; β-endorphin (30-31)), a non-opioid peptide derived from β-endorphin processing, modulates neuropeptide Y (NPY)-induced feeding and hypothalamic mRNA expression of peptide hormones in male broiler chicks. Intracerebroventricular injection of NPY (235 pmol) generated a hyperphagic response in ad libitum chicks within 30 min. Co-administration of Gly-Gln (100 nmol) attenuated this response, inducing a 30 % decrease. This was not attributable to Gly-Gln hydrolysis because co-administration of glycine (Gly) and glutamine (Gln) had no effect on NPY-induced hyperphagia. Gly-Gln injected alone also showed no effect. The hypothalamic pro-opiomelanocortin mRNA expression in the co-injection group was significantly higher than that in the NPY alone group. These data indicate that endogenous Gly-Gln may contribute to regulate feeding behavior via the central melanocortin system in chicks and acts as a counter regulator of the neural activity in energy metabolism.

Keywords: Chick; Feeding behavior; Glycyl-glutamine (Gly-Gln); Neuropeptide Y (NPY); β-Endorphin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chickens
  • Dipeptides / pharmacology*
  • Eating / drug effects*
  • Hyperphagia / metabolism*
  • Hypothalamus / drug effects*
  • Hypothalamus / metabolism
  • Male
  • Neuropeptide Y / pharmacology*
  • Pro-Opiomelanocortin / metabolism*

Substances

  • Dipeptides
  • Neuropeptide Y
  • glycylglutamine
  • Pro-Opiomelanocortin