Biosynthesis of Choline-Containing Lipids by Ruminant Mammary Tissue

Abstract

Ruminant mammary tissues utilized cytidinediphosphocholine-l,2-14C for biosynthesis of the choline-containing lipids, i.e., phosphatidylcholine, lysophosphatidylcholine, and sphingomyelin, which were secreted into milk. Experiments performed both in vivo and in vitro revealed that phosphatidylcholine always attained the highest specific activity. The radioactivity in the phosphatidylcholine fraction decreased rapidly compared to that of the lysophosphatidylcholine and sphingomyelin fractions. The rate of decrease of the specific activity of phosphatidylcholine was consistent with the suggestion that two discrete pools of this compound are present in lactating mammary tissue. © 1969, American Dairy Science Association. All rights reserved.