title: Effects of vitamin B-12 deprivation on phospholipid fatty acid patterns in liver and brain of rats fed high and low levels of linoleate in low methionine diets.
abstract: Experiments were conducted to determine how 20 weeks of deprivation of vitamin B-12 (B-12) would influence polyunsaturated fatty acid (PUFA) patterns in cerebral and liver phospholipids of female rats. All experimental diets included 24% soybean protein and either 3.5 of 0.35% of linoleate (18:2). Deprivation of B-12 and restricted intakes of 18:2 significantly inhibited growth of the rats. Rats depleted of B-12 had 6.7 times more methylmalonic acid in their liver, and significantly more odd-numbered acids (15:0 + 17:0) were present in phosphatidyl choline (PC) of their liver and cerebrum. Deprivation of B-12 promoted 63.3 to 97.3% increases of 18:2 in PC and phosphatidyl ethanolamine (PE) of the liver. Rats deprived of B-12 had significantly less arachidonate (20:4 omega 6) and 22:5 omega 6 in their liver PC, as well as smaller amounts of 20:4 omega 6 and 22:6 omega 3 in their cerebral PC. Some of the observed changes appear to be due to a significant interaction between the effects of B-12 and linoleate. Changes in PUFA patterns of cerebral and hepatic PC suggest that B-12 deprivation may interfere with the conversion of 18:2 omega 6 leads to 20:4 omega 6 leads to 22:5 omega 6. Some of the observed changes may also be related to an inhibited ability to convert PE to PC.
mesh_terms: D000818:Animals; D001835:Body Weight; D001921:Brain / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005227:Fatty Acids / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D005260:Female; D008041:Linoleic Acids / Q000008:administration & dosage; D008099:Liver / Q000378:metabolism*; D008715:Methionine / Q000008:administration & dosage; D009929:Organ Size; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D051381:Rats; D014806:Vitamin B 12 Deficiency
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008041:Linoleic Acids; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D008715:Methionine