Effects of paraventricular nucleus injection of CCK-8 on plasma CCK-8 levels in rats

J. Ernie Blevins, Frederick G. Hamel, Elizabeth Fairbairn, B. Glenn Stanley, Roger D. Reidelberger

Research output: Contribution to journalArticle

19 Scopus citations

Abstract

The aim of the study was to determine whether paraventricular nucleus (PVN) injection of an anorexic 500-pmol dose of cholecystokinin (CCK)-8 could increase plasma CCK-8 levels sufficiently to suppress feeding by a peripheral mechanism. Rats received PVN injections of CCK-8 either alone or with 3H- labelled propionylated CCK-8 (3H-pCCK-8) and plasma samples were taken at various times from 3 to 120 min post-injection. Plasma CCK-8 levels were estimated from measurements of both total plasma CCK-like immunoreactivity (CCK-LI) and 3H-pCCK-8 activity. PVN injections of CCK-8 and 3H-pCCK-8 produced estimated peak increases in plasma CCK-8 of 15 ± 11 and 22 ± 3 pM, respectively. The i.v. infusion of CCK-8 doses (0.2 and 1 nmol/kg h) that bracketed the threshold dose for suppression of feeding, increased plasma CCK-LI from a basal level of 6 ± 1 to 49 ± 10 and 166 ± 36 pM, respectively. The i.v. injections of 600 and 4800 pmol of CCK-8 did not suppress feeding. These results suggest that PVN injection of an anorexic 500-pmol dose of CCK-8 does not increase plasma CCK-8 levels sufficiently to suppress feeding by a peripheral mechanism. (C) 2000 Elsevier Science B.V.

Original languageEnglish (US)
Pages (from-to)11-20
Number of pages10
JournalBrain Research
Volume860
Issue number1-2
DOIs
StatePublished - Mar 31 2000

Keywords

  • Appetite regulation
  • Brain
  • Neuropeptide
  • Satiety

ASJC Scopus subject areas

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

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