Effects of retinoic acid administration and dietary vitamin A supplementation on leptin expression in mice: lack of correlation with changes of adipose tissue mass and food intake

Biochim Biophys Acta. 2005 May 30;1740(2):258-65. doi: 10.1016/j.bbadis.2004.11.014. Epub 2004 Dec 10.

Abstract

Retinoic acid (RA) administration and chronic vitamin A supplementation were reported to inhibit adipose tissue leptin expression in rodents, but the impact of this effect on food intake and its relationship with changes of body adiposity was not analyzed. Here, we have studied the effects of RA administration at three different doses on body weight, adipose tissue mass, food intake, adipose tissue leptin expression and circulating leptin levels in NMRI mice; the effects of chronic vitamin A supplementation with a 40-fold excess retinyl palmitate on the same parameters in NMRI and C57BL/6J mice; and the effects of RA and retinoid receptors agonists on leptin expression in brown and white adipocyte cell model systems. The results show that vitamin A down-regulates leptin expression in white and brown adipose tissue and circulating leptin levels independently of changes of adipose tissue mass and, for the first time to our knowledge, that this effect does not correlate with increased food intake. They also demonstrate a direct inhibitory effect of RA on leptin expression in both white and brown adipocyte cell cultures, and constitute first proof of the involvement of both RA receptors (RARs) and rexinoid receptors (RXRs) in this effect. Reduction of leptin levels by specific nutrients is of potential interest from a clinical point of view.

Publication types

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

MeSH terms

  • 3T3-L1 Cells
  • Adipose Tissue / cytology
  • Adipose Tissue / drug effects
  • Adipose Tissue / metabolism
  • Animals
  • Diet
  • Dietary Supplements
  • Down-Regulation
  • Eating / drug effects
  • Energy Intake / drug effects
  • Leptin / biosynthesis*
  • Leptin / blood
  • Leptin / genetics*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • RNA, Messenger / biosynthesis
  • Receptors, Retinoic Acid / agonists
  • Retinoic Acid Receptor alpha
  • Retinoid X Receptors / agonists
  • Tretinoin / administration & dosage
  • Tretinoin / pharmacology*
  • Vitamin A / administration & dosage
  • Vitamin A / pharmacology*

Substances

  • Leptin
  • RNA, Messenger
  • Rara protein, mouse
  • Receptors, Retinoic Acid
  • Retinoic Acid Receptor alpha
  • Retinoid X Receptors
  • Vitamin A
  • Tretinoin