title: Sexually dimorphic activation of liver and brain phosphatidylethanolamine N-methyltransferase by dietary choline deficiency.
abstract: Phosphatidylethanolamine N-methyltransferase (PEMT) activity was measured by a radioenzymatic assay in homogenates of brain and liver obtained from Sprague Dawley rats fed a choline-free or control (0.3 g/kg of choline chloride) diet for seven days. Choline deficiency increased PEMT activity in the liver of male rats by 34% but had no effect on hepatic PEMT in females. In contrast, brain PEMT activity was increased in brain of choline deficient females (by 49%) but was unaltered in males. Activation of the PE methylation pathway in female brain may constitute a compensatory mechanism to sustain PC synthesis during choline deficiency.
authors.affiliation: Department of Pathology and Laboratory Medicine, Boston University School of Medicine, MA 02118, USA.
authors.forename: P I
authors.initials: PI
authors.lastname: Johnson
authors.forename: J K
authors.initials: JK
authors.lastname: Blusztajn
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002794:Choline / Q000008:administration & dosage / Q000494:pharmacology; D002796:Choline Deficiency / Q000201:enzymology*; D004789:Enzyme Activation; D005260:Female; D008099:Liver / Q000201:enzymology*; D008297:Male; D008780:Methyltransferases / Q000378:metabolism*; D050918:Phosphatidylethanolamine N-Methyltransferase; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics
chemical_list: D008780:Methyltransferases; D050918:Phosphatidylethanolamine N-Methyltransferase; D002794:Choline