Odd-Numbered Fatty Acids in Phosphatidyl Choline Versus Phosphatidyl Ethanolamine of Vitamin B 12 -Deprived Rats 1

Abstract

Abstract

In response to a 20-week dietary deficiency of vitamin B₁₂ rats accumulated two to four times more heptadecanoic acid (17:0) and pentadecanoic acid (15:0) in phosphatidyl choline (PC) of their cerebrum. Considerably smaller amounts of these odd-numbered fatty acids (ONFA) were present in phosphatidyl ethanolamine (PE) of either the cerebrum or liver of rats deprived of, or supplemented with, vitamin B₁₂. Vitamin B₁₂-deficient rats had twice as much ONFA in PC of their cerebrum than in PC of their liver, and the vitamin deficiency had little or no effect on the amounts of ONFA in PE of the cerebrum or liver. The greater incorporation of ONFA into cerebral PC appears to be correlated with a greater abundance of palmitic acid (16:0) and related chain length—even-numbered fatty acids (14:0) and 16:1) in this phospholipid of the rat. Similar relationships between the abundance of ONFA and 16:0 in neural PC were previously found in an infant with genetically defective B₁₂—coenzyme systems.