Effect of magnesium deficiency on delta 6 desaturase activity and fatty acid composition of rat liver microsomes

Lipids. 1989 Aug;24(8):727-32. doi: 10.1007/BF02535212.


Experimental Mg2+ deficiency was induced in a group of rats by feeding them a Mg2+-deficient diet for 23 days. They were pair-fed to compare with a control group of rats fed a Mg2+-sufficient diet. In the Mg2+-deficient group the plasma total cholesterol and triglyceride levels were increased while HDL-cholesterol was decreased. In the Mg2+-deficient group the plasma level of thiobarbituric acid reacting substances (TBARS) used as a measure for lipid peroxidation was increased. The increase was attributed to the increased cytosolic Ca2+ in Mg2+-deficiency which can cause: 1) increase of hydro and endoperoxide levels as a consequence of the increase of arachidonic acid release and eicosanoid synthesis in Mg2+-deficiency, and 2) inhibition of the mitochondrial respiratory activity and activation of Ca2+-dependent proteases which may activate the conversion of xanthine dehydrogenase to xanthine oxidase which generates active O2 species. In the Mg2+-deficient group, the fatty acid composition of the liver microsomes indicated a slower rate of conversion of linoleic acid to arachidonic acid which was consistent with the decrease of delta 6 desaturase activity in liver microsomes of Mg2+-deficient rats as measured in vitro. The decrease of delta 6 desaturase activity was attributed to the lower concentration of actual enzyme molecules as a result of the decreased rate of protein synthesis in Mg2+-deficiency. The possible effects of the increased catecholamine release in Mg2+-deficiency are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Arachidonic Acid
  • Arachidonic Acids / metabolism
  • Cholesterol / blood
  • Cholesterol, HDL / blood
  • Coenzyme A / metabolism
  • Cyclic AMP / metabolism
  • Fatty Acid Desaturases / metabolism*
  • Fatty Acids / metabolism*
  • Fatty Acids, Nonesterified / metabolism
  • Hydroxymethylglutaryl CoA Reductases / metabolism
  • Linoleoyl-CoA Desaturase
  • Lipid Peroxides / blood
  • Magnesium / pharmacology
  • Magnesium Deficiency / enzymology*
  • Male
  • Microsomes, Liver / enzymology*
  • Rats
  • Rats, Inbred Strains
  • Thiobarbiturates
  • Triglycerides / blood


  • Arachidonic Acids
  • Cholesterol, HDL
  • Fatty Acids
  • Fatty Acids, Nonesterified
  • Lipid Peroxides
  • Thiobarbiturates
  • Triglycerides
  • Arachidonic Acid
  • Adenosine Triphosphate
  • Cholesterol
  • Cyclic AMP
  • Hydroxymethylglutaryl CoA Reductases
  • Fatty Acid Desaturases
  • Linoleoyl-CoA Desaturase
  • Magnesium
  • thiobarbituric acid
  • Coenzyme A