Fatty Acid Transport across Rat Brain Microvessel Endothelial Cells (RBMEC) Requires a Fatty Acid Acceptor

The Blood Brain Barrier (BBB) is the physical protective barrier between the cerebral blood vessels and parts of the central nervous system. Endothelial cells lining the blood capillaries are packed tightly thus regulating the transport of substances from the blood into the brain, including fatty acids. Fatty acids are essential for both the developing and adult mammalian brain. Since most of the fatty acids in the brain enter from the blood, we examined the mechanism of transport across the BBB. Rat Brain Microvessel Endothelial cells (RBMEC) were plated onto 12 transwell plate inserts for these permeability studies. RBMECs were then incubated for up to 4 h with 0.1 μM [ 14 C]oleic acid in the apical medium and the radioactivity was temporally determined in the basolateral medium in the absence or presence of bovine serum albumin. There was a near linear increase in [ 14 C]oleic acid incorporation into the basolateral medium with time in the presence of either regular bovine serum albumin or fatty acid free bovine serum albumin. In contrast, no [ 14 C]oleic acid incorporation into the basolateral media was observed in the absence of albumin, indicating that the permeability layer was intact and that a fatty acid acceptor is a requirement for fatty acid transport across the permeability layer of these cells. (Supported by grants from the Manitoba Health Research Council and the Canada Research Chair program)