Effects of dietary calcium on adipocyte lipid metabolism and body weight regulation in energy-restricted aP2-agouti transgenic mice

FASEB J. 2001 Feb;15(2):291-3. doi: 10.1096/fj.00-0584fje. Epub 2000 Dec 8.

Abstract

We have demonstrated previously a regulatory role for intracellular Ca2+ ([Ca2+]i) in adipocyte lipogenesis and lipolysis and have recently reported that 1,25-(OH)2-D increases adipocyte [Ca2+]i, which causes increased lipogenesis and decreased lipolysis. We have now tested the hypothesis that suppressing 1,25-(OH)2-D by increasing dietary calcium will suppress adipocyte [Ca2+]i, thereby facilitating weight loss by stimulating lipolysis and inhibiting lipogenesis in calorically (Kcal)-restricted (70% of ad lib) aP2-agouti transgenic (aP2-a) mice. Mice (aP2-a) exhibiting a pattern of obesity gene expression similar to humans were fed a low-Ca (0.4%)/high-fat/high-sucrose diet for six weeks, resulting in a 27% and twofold increase in body weight and total fat pad mass, respectively, with a twofold increase in adipocyte [Ca2+]i pad lib or Kcal-restricted (70% of ad lib) on this diet either unsupplemented (basal) or with 25% or 50% of the protein replaced by non-fat dry milk (medium or high) dairy or supplemented with CaCO3 to 1.2% Ca for six weeks. Adipocyte [Ca2+]i was unaffected by Kcal restriction but was reduced markedly by all three high Ca diets (290 vs. 130 nM, p2+]i and thereby reduce energy storage and increase thermogenesis during Kcal restriction.

MeSH terms

  • Adipocytes / drug effects
  • Adipocytes / metabolism*
  • Adipose Tissue / anatomy & histology
  • Adipose Tissue / cytology
  • Adipose Tissue / physiology*
  • Animals
  • Body Temperature Regulation
  • Body Weight* / genetics
  • Calcitriol / pharmacology
  • Calcium, Dietary / pharmacology*
  • Diet, Reducing
  • Energy Metabolism* / genetics
  • Ion Channels
  • Lipid Metabolism*
  • Lipolysis
  • Membrane Transport Proteins*
  • Mice
  • Mice, Inbred Strains
  • Mice, Transgenic
  • Mitochondrial Proteins*
  • Models, Biological
  • Obesity / genetics
  • Obesity / physiopathology*
  • Proteins / genetics
  • Proteins / metabolism
  • Uncoupling Protein 2

Substances

  • Calcium, Dietary
  • Ion Channels
  • Membrane Transport Proteins
  • Mitochondrial Proteins
  • Proteins
  • Uncoupling Protein 2
  • Calcitriol