Central melanocortin receptor agonist reduces spontaneous and scheduled meal size but does not augment duodenal preload-induced feeding inhibition

Anthony V. Azzara, Jeremy P. Sokolnicki, Gary J. Schwartz

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

Central melanocortin (MC) receptor agonists inhibit food intake and may be downstream mediators of the effects of central leptin, which (1) reduces food intake by selectively decreasing meal size and (2) augments the feeding-inhibitory effects of gastrointestinal food stimuli. Central administration of the MC-3/4 receptor (MC-3/4R) agonist, MTII, inhibits feeding in rats, but its effects on meal pattern and potential interactions with gastrointestinal controls of food intake remain unclear. We examined meal patterns and intake in male Sprague-Dawley rats following central intracerebroventricular administration of MTII (0.01 - 1.0 nmol) in two situations: (1) during daytime 60-min scheduled access to liquid glucose (12.5%) in combination with a duodenal preload of 12.5% glucose or physiological saline (4.4 ml/10 min), and (2) during subsequent overnight access to 45 mg of solid chow pellets. Both duodenal glucose preloads and MTII reduced subsequent glucose intake. However, no dose of MTII augmented the reductions in food intake produced by duodenal glucose alone. During overnight access to pelleted chow, the 0.1- and 1.0-nmol doses of MTII reduced food intake, meal size, meal duration, and body weight, and increased the satiety ratio (duration of intermeal interval/preceding meal size) but did not change meal frequency. The present data (1) demonstrate that MTII, like leptin, reduces food intake by a selective reduction in meal size and not meal frequency, and (2) suggest that MTII increases the feeding-inhibitory potency of negative feedback signals critical to the control of meal size during spontaneous chow access, but not scheduled access to palatable liquid nutrient solutions.

Original languageEnglish (US)
Pages (from-to)411-416
Number of pages6
JournalPhysiology and Behavior
Volume77
Issue number2-3
DOIs
StatePublished - Nov 2002
Externally publishedYes

Fingerprint

Melanocortin Receptors
Meals
Eating
Glucose
Leptin
Receptor, Melanocortin, Type 3
Receptor, Melanocortin, Type 4
Sprague Dawley Rats

Keywords

  • Energy homeostasis
  • Gut-brain communication
  • MTII

ASJC Scopus subject areas

  • Behavioral Neuroscience
  • Physiology (medical)

Cite this

Central melanocortin receptor agonist reduces spontaneous and scheduled meal size but does not augment duodenal preload-induced feeding inhibition. / Azzara, Anthony V.; Sokolnicki, Jeremy P.; Schwartz, Gary J.

In: Physiology and Behavior, Vol. 77, No. 2-3, 11.2002, p. 411-416.

Research output: Contribution to journalArticle

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