title: Role of lactate in the brain energy metabolism: revealed by Bioradiography.
abstract: To elucidate the role of lactate in the brain, we used a novel method, 'Bioradiography', in which the dynamic process could be followed in living slices by use of positron-emitter-labeled compounds and imaging plates. We studied the incorporation of 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) into rat brain slices incubated in oxygenated Krebs-Ringer solution. Under the glucose-free condition, [18F]FDG uptake rate in the cerebral cortex decreased with time and plateaued within 350 min but the addition of 5 mM lactate made the [18F]FDG uptake linear. When an inhibitor of the lactate transporter, 0.5 mM alpha-cyano-4-hydroxycinnamate (4-CIN) was applied to the glucose-free solution, the uptake rate decreased. Under the normal glucose condition, [18F]FDG uptake linearly increased for 6 h, but when 10 mM lactate was applied, the uptake rate decreased. In contrast, when 0.5 mM 4-CIN was applied to the normal glucose solution, [18F]FDG uptake rate increased. These results suggest that exogenous and endogenous lactate can substitute for glucose in the brain.
authors.affiliation: Department of Physiology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Tanaka
authors.forename: Fusao
authors.initials: F
authors.lastname: Nakamura
authors.forename: Shigekazu
authors.initials: S
authors.lastname: Mizokawa
authors.forename: Akira
authors.initials: A
authors.lastname: Matsumura
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Matsumura
authors.forename: Tetsuhito
authors.initials: T
authors.lastname: Murata
authors.forename: Makoto
authors.initials: M
authors.lastname: Shigematsu
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Kageyama
authors.forename: Hironobu
authors.initials: H
authors.lastname: Ochi
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D003373:Coumaric Acids / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000502:physiology*; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D066298:In Vitro Techniques; D019344:Lactic Acid / Q000378:metabolism*; D008297:Male; D011859:Radiography / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D003373:Coumaric Acids; D019788:Fluorodeoxyglucose F18; C007175:alpha-cyano-4-hydroxycinnamate; D019344:Lactic Acid; D005947:Glucose