Fasting increases palmitic acid incorporation into rat hind-limb intramuscular acylglycerols while short-term cold exposure has no effect

Acta Physiol Hung. 2011 Sep;98(3):359-66. doi: 10.1556/APhysiol.98.2011.3.13.

Abstract

The aim of the study was to investigate the palmitic acid incorporation into intramuscular acylglycerols in perfused hind-limb skeletal muscles of different fibre types in rats either fasted for 48 h or exposed to cold (6 °C) for 12 h. Hind-limb preparations of fasted and cold exposed rats were perfused with buffers containing tritium labelled and cold palmitic acid. Palmitic acid incorporation into intracellular lipid pools in the soleus, plantaris, red and white gastrocnemius and red and white quadriceps was measured. It was found that fasting increased approximately 2-fold palmitic acid incorporation in all muscles examined regardless of the fibre type composition of the muscle. On the other hand, exposure to cold had no effect on the palmitic acid incorporation into intramuscular acylglycerols regardless the muscle fibre type. The increased incorporation of palmitic acid into acylglycerols in fasted animals is in line with data showing that 48 h fasting stimulates the expression of plasma membrane proteins putatively facilitating fatty acid uptake. It appears that although 12 h cold exposure increases the use of fatty acids as energy substrates it does not alter the incorporation of palmitic acid into intramuscular acylglycerols in the perfused rat hind-limb.

MeSH terms

  • Analysis of Variance
  • Animals
  • Cold Temperature*
  • Fasting / metabolism*
  • Glycerides / metabolism*
  • Hindlimb
  • Male
  • Muscle Fibers, Fast-Twitch / metabolism
  • Muscle Fibers, Slow-Twitch / metabolism
  • Muscle, Skeletal / cytology
  • Muscle, Skeletal / metabolism*
  • Palmitic Acid / metabolism*
  • Perfusion
  • Rats
  • Rats, Wistar
  • Time Factors

Substances

  • Glycerides
  • Palmitic Acid