Effects of intra-PVN injections of d- and l-norephedrine on feeding in rats

Brain Res Bull. 1993;32(4):443-5. doi: 10.1016/0361-9230(93)90213-u.

Abstract

Phenylpropanolamine (PPA) is thought to inhibit feeding by activation of alpha 1-adrenergic receptors within the paraventricular hypothalamus (PVN). Systemic injections of the PPA component enantiomers, d- and l-norephedrine (NEP), result in differential suppression of feeding (l-NEP more potent than d-NEP). Whether the norephedrine racemates induce differential anorexia subsequent to injection into the PVN is unknown. In the present study, adult male rats received intra-PVN injections of the d- and l-norephedrine enantiomers (0, 80, 160, and 240 nmol). Significantly greater anorexia was obtained for l-NEP relative to d-NEP. These results document a stereospecific effect of the norephedrine enantiomers within the PVN in inhibiting food intake and suggest that the interaction of these enantiomers with PVN alpha 1-adrenoceptors may mediate the similar difference in potency noted for systemic injections of d- and l-norephedrine.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anorexia / chemically induced
  • Dose-Response Relationship, Drug
  • Feeding Behavior / drug effects*
  • Male
  • Microinjections
  • Norepinephrine / administration & dosage
  • Norepinephrine / pharmacology*
  • Paraventricular Hypothalamic Nucleus / drug effects
  • Paraventricular Hypothalamic Nucleus / physiology*
  • Rats
  • Rats, Sprague-Dawley
  • Stereoisomerism

Substances

  • Norepinephrine