Rostral hypothalamus: a new neuroanatomical site of neurochemically-induced emesis in the cat.

Published

Journal Article

The localized effect of noradrenergic agonists administered directly in the anterior hypothalamic preoptic area (AH/POA) in inducing emesis in the cat was investigated. Of the noradrenergic agonists tested, which included norepinephrine, clonidine, phenylephrine and methoxamine, only clonidine in doses of 5.0-50.0 micrograms was found to evoke emesis consistently when micro-injected in a volume of 1.0 microliter into AH/POA of the unrestrained cat. The emetic response to clonidine was short-lasting, generally dose-dependent in terms of latency and frequency, and occurred in bouts of one to three episodes. The sequence of the vomiting response, beginning with licking and retching, functionally resembled a normal pattern of an emetic response. The clonidine-induced emesis was not antagonized by the following antagonists micro-injected in AH/POA just prior to clonidine: alpha-adrenergic blocking agents, yohimbine, RX 781094 and phentolamine; the antimuscarinic drug, atropine; the serotonin antagonist, methysergide; the opioid antagonist, naloxone; and the dopamine antagonist, chlorpromazine. Therefore, it would appear that clonidine-induced emesis is not mediated by alpha noradrenergic, serotonergic, dopaminergic, muscarinic and opiate receptor systems within the AH/POA of the cat. Finally, the obtained results show that apart from the area postrema and a circumscribed zone of the brain-stem reticular formation, the hypothalamus is now implicated as a neuroanatomical site in the central nervous system mechanism underlying neurochemically-induced emesis.

Full Text

Duke Authors

Cited Authors

  • Beleslin, DB; Rezvani, AH; Myers, RD

Published Date

  • August 1987

Published In

Volume / Issue

  • 19 / 2

Start / End Page

  • 239 - 244

PubMed ID

  • 2889512

Pubmed Central ID

  • 2889512

International Standard Serial Number (ISSN)

  • 0361-9230

Digital Object Identifier (DOI)

  • 10.1016/0361-9230(87)90089-x

Language

  • eng

Conference Location

  • United States