IN-VIVO INCORPORATION FROM PLASMA OF RADIOLABELED PALMITATE AND ARACHIDONATE INTO RAT-BRAIN MICROVESSELS

The microvascular endothelium must respond efficiently to the metaboli c needs of the brain for normal brain function. To do this, endothelia l cells have metabolic pathways that utilize substrates not primary to the metabolic needs of the brain as a whole. Thus, endothelial utiliz ation of glucose is minimized, and saturated, long-chain fatty acids, such as palmitate, become a major source of fuel for oxidative metabol ism and active transport processes (Goldstein, 1979). Previous assessm ent of fatty acid metabolism in cerebral microvessels has relied upon in vitro approaches involving cultured endothelial cells or isolated m icrovessels. The present study, utilizing radiolabeled fatty acids int ravenously infused in vivo, is the first to report on fatty acid incor poration within cerebral microvessels of an awake animal.