Neuropeptide Y induced inhibition of noradrenaline release in rat hypothalamus: Role of receptor subtype and nitric oxide

Marcela Bitran, Wildo Tapia, Eliseo Eugenin, Patricio Orio, Mauricio P. Boric

Research output: Contribution to journalArticle

25 Scopus citations


We aimed at characterizing the receptor subtype and the signaling pathway involved in the inhibitory effect of neuropeptide Y on the release of endogenous noradrenaline from rat hypothalamus. Slices of hypothalamus were stimulated with two trains of electrical pulses, and the release of noradrenaline and nitric oxide was measured. The electrical stimulation of hypothalamic slices induced a consistent release of both endogenous noradrenaline and NO. Neuropeptide Y inhibited concentration dependently the stimulated noradrenaline release. Similarly, agonists for neuropeptide Y Y1, Y2 and Y5 receptors inhibited noradrenaline release, albeit with a potency lower than neuropeptide Y. GW1229, a selective neuropeptide Y Y1 receptor antagonist counteracted the effect of neuropeptide Y, but not that of PYY-(3-36), an agonist active at neuropeptide Y Y5 and Y2 receptors. These results indicate that the inhibitory effect of neuropeptide Y is likely mediated by several receptor subtypes, including neuropeptide Y Y1, Y5 and possibly Y2 receptors. One μM NPY significantly enhanced NO release induced by the electrical stimulation. N(G)-monomethyl-L-arginine, an inhibitor of nitric oxide synthase, abolished NO release and blocked the inhibitory effect of neuropeptide Y on noradrenaline release. We conclude that nitric oxide participates in the signaling pathway of neuropeptide Y in the rat hypothalamus. Copyright (C) 1999 Elsevier Science B.V.

Original languageEnglish (US)
Pages (from-to)87-93
Number of pages7
JournalBrain Research
Issue number1-2
StatePublished - Dec 18 1999
Externally publishedYes



  • [Leu,Pro]neuropeptide Y
  • N(G)-monomethyl-L-arginine (L-NMMA)
  • Neuropeptide Y-(13-36)
  • Nitric oxide
  • NPY
  • PYY-(3-36)

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Clinical Neurology
  • Developmental Biology

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