High-fat diet-induced alterations in the feeding suppression of low-dose nisoxetine, a selective norepinephrine reuptake inhibitor

J Obes. 2013:2013:457047. doi: 10.1155/2013/457047. Epub 2013 Jan 30.

Abstract

Central noradrenergic pathways are involved in feeding and cardiovascular control, physiological processes altered by obesity. The present studies determined how high-fat feeding and body weight gain alter the sensitivity to the feeding suppression and neural activation to a selective norepinephrine reuptake inhibitor, nisoxetine. Acute administration of nisoxetine (saline: 0, 3, 10, and 30 mg/kg; i.p.) resulted in a dose-dependent reduction in the 24 h refeeding response in male Sprague Dawley rats maintained on standard chow. In a similar fashion, nisoxetine resulted in reductions in blood pressure and a compensatory increase in heart rate. From these studies, the 3 mg/kg dose was subthreshold. In a separate experiment, however, 10 wk exposure to a high-fat diet (60% fat) resulted in weight gain and significant feeding suppression following administration of nisoxetine (3 mg/kg) compared with animals fed a control diet (10% fat). Nisoxetine (3 mg/kg) also resulted in greater neural activation, as measured by c-Fos immunohistochemistry, in the arcuate nucleus of the hypothalamus in animals exposed to the high-fat diet. Such data indicate acute nisoxetine doses that suppress food intake can impact cardiovascular measures. It also suggests that the feeding suppression to a low-dose nisoxetine is enhanced as a result of high-fat diet and weight gain.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Appetite Regulation / drug effects
  • Appetite Regulation / physiology
  • Arcuate Nucleus of Hypothalamus / chemistry
  • Blood Pressure / drug effects
  • Diet, High-Fat / adverse effects*
  • Dose-Response Relationship, Drug
  • Eating / drug effects*
  • Fluoxetine / administration & dosage
  • Fluoxetine / analogs & derivatives*
  • Heart Rate / drug effects
  • Immunohistochemistry
  • Male
  • Norepinephrine / antagonists & inhibitors*
  • Norepinephrine / physiology*
  • Proto-Oncogene Proteins c-fos / analysis
  • Rats
  • Rats, Sprague-Dawley
  • Weight Gain / drug effects

Substances

  • Proto-Oncogene Proteins c-fos
  • Fluoxetine
  • nisoxetine
  • Norepinephrine