An effect of vitamin B 12 deficiency in tissue culture.

Rat glial cells were grown in tissue culture in vitamin BW deficient medium. As the intracellular level of coenzyme Bls decreased, the cells made increasing amounts of two unusual fatty acids. The fatty acids were unbranched acids with 15 and 17 carbon atoms and arose as the cells progressively lost the ability to metabolize propionic acid through the BIz-requiring methylmalonyl-CoA mutase reaction. The levels of the 15and 17-carbon acids returned to normal when the cultures were supplemented with vitamin BD The possible importance of similar fatty acid changes in human vitamin Blz deficiency and in disorders of 3and 4carbon acid metabolism is speculated.