Role of lactate in the brain energy metabolism: revealed by Bioradiography.
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.
Tanaka
Masaaki
M
Department of Physiology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan.
Nakamura
Fusao
F
Mizokawa
Shigekazu
S
Matsumura
Akira
A
Matsumura
Kiyoshi
K
Murata
Tetsuhito
T
Shigematsu
Makoto
M
Kageyama
Katsuhiro
K
Ochi
Hironobu
H
Watanabe
Yasuyoshi
Y
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
D003373:Coumaric Acids; D019788:Fluorodeoxyglucose F18; C007175:alpha-cyano-4-hydroxycinnamate; D019344:Lactic Acid; D005947:Glucose