Testosterone induction of microsomal acyl-CoA reductase and a cytosolic regulatory protein in mouse preputial glands.
Alkyl and alk-1-enyl (plasmalogens) ether-linked glycerolipids are prominent components of many mammalian cells; moreover, an acetylated form of an alkyl phospholipid was recently found to possess potent hypotensive, inflammatory and allergic properties. In our studies, preputial glands of mice were selected as a model to investigate the regulation of factors involved in the biosynthesis of ether-linked lipids, since these glands contain high concentrations of ether-linked neutral lipids that are under the influence of hormonal control. We found that a key enzyme in the ether-lipid metabolic pathway, microsomal acyl-CoA reductase that catalyzes the formation of long-chain fatty alcohols (precursor of the O-alkyl chain), was increased 16-fold after injecting testosterone into male, castrated mice. This induction was highly specific, since testosterone did not affect another microsomal enzyme, NADPH-cytochrome c reductase. Based on kinetics of enzyme activity changes, the half-life of acyl-CoA reductase was calculated to be 61-70 h. In addition, the activity of a cytosolic stimulatory protein for the acyl-CoA reductase (but not for a different cytosolic protein, lactate dehydrogenase) was also enhanced in the testosterone-treated, male, castrated mice. These findings indicate that acyl-CoA reductase is an important regulatory enzyme in the reactions that lead to the formation of the ether bond in glycerolipids and that it is modulated through hormonal control.
D000375:Aging; D000445:Aldehyde Oxidoreductases / Q000096:biosynthesis*; D000818:Animals; D003600:Cytosol / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051379:Mice; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology*; D010413:Penis / Q000254:growth & development / Q000378:metabolism*; D014176:Protein Biosynthesis; D012627:Sebaceous Glands / Q000187:drug effects / Q000378:metabolism*; D013739:Testosterone / Q000494:pharmacology*
D013739:Testosterone; D000445:Aldehyde Oxidoreductases; C021351:hexadecanal dehydrogenase (acylating)