Reduced CCK signaling in obese-prone rats fed a high fat diet

Frank A. Duca, Li Zhong, Mihai Covasa

Research output: Contribution to journalArticlepeer-review

32 Scopus citations

Abstract

Deficits in satiation signaling during obesogenic feeding have been proposed to play a role in hyperphagia and weight gain in animals prone to become obese. However, whether this impaired signaling is due to high fat (HF) feeding or to their obese phenotype is still unknown. Therefore, in the current study, we examined the effects of CCK-8 (0.5, 1.0, 2.0, and 4.0. μg/kg) on suppression of food intake of HF-fed obese prone (OP) and resistant (OR) rats. Additionally, we determined the role of endogenous CCK in lipid-induced satiation by measuring plasma CCK levels following a lipid gavage, and tested the effect of pretreatment with devazepide, a CCK-1R antagonist on intragastric lipid-induced satiation. Finally, we examined CCK-1R mRNA levels in the nodose ganglia. We show that OP rats have reduced feeding responses to the low doses of exogenous CCK-8 compared to OR rats. Furthermore, OP rats exhibit deficits in endogenous CCK signaling, as pretreatment with devazepide failed to abolish the reduction in food intake following lipid gavage. These effects were associated with reduced plasma CCK after intragastric lipid in OP but not OR rats. Furthermore, HF feeding resulted in downregulation of CCK-1Rs in the nodose ganglia of OP rats. Collectively, these results demonstrate that HF feeding leads to impairments in lipid-induced CCK satiation signaling in obese-prone rats, potentially contributing to hyperphagia and weight gain.

Original languageEnglish (US)
Pages (from-to)812-817
Number of pages6
JournalHormones and Behavior
Volume64
Issue number5
DOIs
StatePublished - Nov 2013
Externally publishedYes

Keywords

  • CCK-1R
  • DIO
  • Devazepide
  • High-fat diet
  • Obesity

ASJC Scopus subject areas

  • Endocrinology
  • Endocrine and Autonomic Systems
  • Behavioral Neuroscience

Fingerprint

Dive into the research topics of 'Reduced CCK signaling in obese-prone rats fed a high fat diet'. Together they form a unique fingerprint.

Cite this