This is exemplified by the observation that Pemt −/− mice (mice lacking functional PEMT) will abort at 9–10 days unless fed supplemental choline.While maternal stores of choline are depleted during pregnancy and lactation, the placenta accumulates choline by pumping choline against the concentration gradient into the tissue, where it is then stored in various forms, mostly as acetylcholine. Choline concentrations in amniotic fluid can be ten times higher than in maternal blood. Functions in the fetus
Choline is in high demand during pregnancy as a substrate for building cellular membranes (rapid fetal and mother tissue expansion), increased need for one-carbon moieties (a substrate for methylation of DNA and other functions), raising choline stores in fetal and placental tissues, and for increased production of lipoproteins (proteins containing "fat" portions). In particular, there is interest in the impact of choline consumption on the brain. This stems from cholines use as a material for making cellular membranes (particularly in making phosphatidylcholine). Human brain growth is most rapid during the third trimester of pregnancy and continues to be rapid to approximately five years of age. During this time, the demand is high for sphingomyelin, which is made from phosphatidylcholine (and thus from choline), because this material is used to myelinate (insulate) nerve fibers. Choline is also in demand for the production of the neurotransmitter acetylcholine, which can influence the structure and organization of brain regions, neurogenesis, myelination, and synapse formation.
Later that year "neurine" and sinkaline were shown to be the same substances as Streckers choline. Thus, Bayer was the first to resolve the structure of choline. The compound now known as neurine is unrelated to choline. Discovery as a nutrient
In the early 1930s, Charles Best and colleagues noted that fatty liver in rats on a special diet and diabetic dogs could be prevented by feeding them lecithin, proving in 1932 that choline in lecithin was solely responsible for this preventive effect. In 1998, the US National Academy of Medicine reported their first recommendations for choline in the human diet. == References ==