Rutgers researchers unlock mysteries of vitamin A metabolism during embryonic d...( New Brunswick NJResearchers at Rutge...),Health

New Brunswick, NJResearchers at Rutgers have unlocked some of the mysteries of how the developing embryo reacts to fluctuations in the amount of vitamin A present in the maternal blood stream. Their results are presented in the February 28 issue of the Journal of Biological Chemistry.

The researchers studied the role of LRAT, a protein that facilitates the formation of vitamin A stores in the body, during embryonic development. In particular, they showed how LRAT protects developing tissues from potentially toxic levels of vitamin A that have been ingested by the mother. Although this function of LRAT had previously been hypothesized in adults, this is the first time that its role has been demonstrated during embryonic development.

The developing mammalian embryo is entirely dependent on the maternal circulation for its supply of retinoids, the vitamin A metabolites produced in the body. These are essential nutrients and they control the formation of the embryos heart, central nervous system, eyes and other important organs and tissues. Malformations of the developing embryo can occur when too little, or too much, vitamin A is consumed by the mother.

We were looking for the mechanisms that allow the fetus to maintain adequate amount of retinoids, whether the mother has over- or under-consumed vitamin A, said Dr. Loredana Quadro, an assistant professor in the Department of Food Science and member of the Center for Lipid Research at the Rutgers School of Environmental and Biological Sciences. We also looked at the effects of different levels of vitamin A being transferred from the mother to the fetus.

When vitamin A is ingested, it is converted into retinyl ester (RE) in the intestine from where it is secreted in the bloodstream packaged with other dietary lipids into lipoprotein particles called chylomicrons. The majority of dietary RE reaches the liver, the main body storage site of vitamin A. Under insufficient die
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