Decreased labeling of amino acids by inhibition of the utilization of (/sup 3/H, /sup 14/C)glucose via the hexosemonophosphate shunt in rat brain in vivo
Treatment of rats with 6-aminonicotinamide showed a small but significant decrease in the labeling of amino acids in the brain after injection of (/sup 3/H)acetate. The results of these experiments also gave evidence of the presence of (/sup 3/H)glucose and (/sup 3/H)acetate, and an increase in (/sup 3/H)glucose content in the brain of 6-aminonicotinamide treated rats. To apportion the contribution of (/sup 3/H)glucose formed by gluconeogenesis from (/sup 3/H)acetate to the labeling of amino acids a method was formulated based on the measurement of radioactivity of amino acids, lactate and free sugars in brain after injection of (6-/sup 3/H)glucose or (1-/sup 3/H)glucose relative to that after co-injection of (U-/sup 14/C)glucose or (2-/sup 14/C)glucose. These findings indicated that a significant decrease in the labeling of amino acids from (U-14C)glucose reported previously and again confirmed using (1-/sup 3/H), (6-/sup 3/H), (2-/sup 14/C) or (U-/sup 14/C)glucose in the present investigation was not due to the inhibition of the activities of enzymes of the citric acid cycle. These results support the postulated role of the hexosemonophosphate shunt for the utilization of glucose in providing neurotransmitter amino acids glutamate and gamma-aminobutyrate.
- Research Organization:
- St. George's Hospital Medical School, London, England
- OSTI ID:
- 6132596
- Journal Information:
- Neurochem. Res.; (United States), Journal Name: Neurochem. Res.; (United States) Vol. 9:3; ISSN NERED
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ALDEHYDES
AMINO ACIDS
ANIMALS
BIOLOGICAL MATERIALS
BIOLOGICAL PATHWAYS
BLOOD
BODY
BODY FLUIDS
BRAIN
CARBOHYDRATES
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM
DIGESTIVE SYSTEM
GLANDS
GLUCOSE
HEXOSES
IN VIVO
LABELLED COMPOUNDS
LIVER
MAMMALS
MATERIALS
METABOLISM
MONOSACCHARIDES
NERVOUS SYSTEM
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RATS
RODENTS
SACCHARIDES
TRITIUM COMPOUNDS
VERTEBRATES