Abstract
A new system about the lipid uptake and excrete to a cell was found in an elucidation process on the xenobiotic excretion mechanism. As for this new lipid transport mechanism, it was proved by gene analysis that it was the ABC (ATP-binding cassette) transporter protein which was the multidrug resistance (MDR) gene product which was a xenobiotic excretion pump. The ABC transporter protein uptakes a variety of lipid including phospholipid and cholesterol in a cell and excretes it. Phospholipid transportation in respiratory distress syndrome of the newborn and excretion mechanism of plant sterol had been understood in greater detail by this discovery. The DHA supplied to the fetus is transported from a uterus with precedence than other fatty acids by placenta and fatty acid-binding protein (FABP).The uptake on the brain of the DHA from a uterus to a fetus is controlled by FABP of the brain type, and the gene encoding the protein (FABP7) becomes the target of transcription factor (Pax6) controlling the development of the brain. With adult brain, an LDL receptor is not confirmed in the luminal of the blood-brain barrier (BBB), and that is why the lipids uptake mechanism to brain is still unexplained now.
