Fatty acid uptake and incorporation in brain: studies with the perfusion model.
The contributions of individual components of blood to brain [14C]palmitate uptake and incorporation were studied with the in situ brain perfusion technique in the pentobarbital-anesthetized rat. With whole-blood perfusate, brain unacylated [14C]palmitate uptake was linear with time and extrapolated to zero at T = 0 s of perfusion. Tracer accumulated in brain with a blood-to-brain transfer coefficient of 1.8 +/- 0.1 x 10(-4) mL/s/g (whole cerebral hemisphere). Incorporation into brain lipids was rapid such that approximately 40% of tracer in brain at 45 s of perfusion was in cerebral phospholipids and neutral lipids. Similar rates of uptake were obtained during unacylated [14C]palmitate perfusion in whole rat plasma, serum, or artificial saline containing 2-3% albumin, suggesting that albumin has a key role in determining [14C]palmitate uptake in brain. The excellent match in brain uptake rates between whole blood and albumin-containing saline fluid suggests that the perfusion technique will be useful method for quantifying the individual contributions of blood constituents and albumin binding on brain [14C]palmitate uptake.
Smith
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QR
Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo 79106, USA. quentin@cortex.ama.ttuhsc.edu
Nagura
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H
D000818:Animals; D001769:Blood; D001812:Blood-Brain Barrier; D001921:Brain / Q000378:metabolism*; D050356:Lipid Metabolism; D008297:Male; D019308:Palmitic Acid / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D010477:Perfusion; D010949:Plasma; D051381:Rats; D017207:Rats, Sprague-Dawley; D012709:Serum Albumin / Q000378:metabolism; D012965:Sodium Chloride
D012709:Serum Albumin; D019308:Palmitic Acid; D012965:Sodium Chloride