Quantitative comparison of transport and phosphorylation of three fluorosugars in the isolated rat heart

Conference · Sun Jan 01 04:00:00 EST 1984 · J. Nucl. Med.; (United States)

OSTI ID:6842176

Holden, J E; Halama, J R; Gatley, S J; Ng, C K; DeGrado, T R

Bolus injection and coincidence counting of residue curves in an intact isolated rat heart preparation were used for the quantitative comparison of myocardial cell membrane transport and myocardial phosporylation rates of the F-18 labeled fluorosugars 2-deoxy-2-fluoro-D-glucose (2FDG), 3-deoxy-3-fluoro-D-glucose (D-3FDG), and 3-deoxy-3-fluor-L-glucose (L-3FGD). Transport and phosphorylation rates were quantitated using a compartmental model incorporating interstitial and cellular sugar and cellular sugar-6-phosphate. Affinity of cell membrane carrier molecules for D-3FDG was about half that for 2FDG, and transport of both fluorosugars was inhibited by increased glucose concentration. Phosphorylation rate of glucose was determined simultaneously from the rate of release of tritiated water from 2-(H-3)-glucose dissolved in the perfusion medium. Phosphorylation lumped constants of 2FDG and D-3FDG averaged 0.99 +- 0.05 and 0.10 +- 0.01 respectively, and phosphorylation of both analogs clearly demonstrated competition with glucose in the perfusion medium. The rate of phosphatase catalysed hydrolysis of D-3FDG-6-phosphate was twice that of 2FDG-6-phosphate. This, along with the reduced phosphorylation rate, strongly moderates the accumulation of 3FDG-6-phosphate in tissue. Kinetics of L-3FDG were independent of perfusate glucose concentration, and were consistent with access to the cell interior only by simple diffusion. However, fitting of L-3FDG residue curves unexpectedly but unambiguously required three tissue compartments.

• Research Organization: Medical Physics Dept., Univ. of Wisconsin, Madison, WI
• OSTI ID: 6842176
• Report Number(s): CONF-840619-
• Conference Information: Journal Name: J. Nucl. Med.; (United States) Journal Volume: 25:5
• Country of Publication: United States
• Language: English

Related Subjects

551000* -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
ANTIMETABOLITES
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CARBOHYDRATES
CARDIOVASCULAR SYSTEM
CHEMICAL REACTIONS
DISSOLUTION
DRUGS
FLUORINE 18
FLUORINE ISOTOPES
FLUORODEOXYGLUCOSE
HEART
HOURS LIVING RADIOISOTOPES
ISOTOPES
LIGHT NUCLEI
MAMMALS
MEMBRANE TRANSPORT
MONOSACCHARIDES
MUSCLES
MYOCARDIUM
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PHOSPHORYLATION
RADIOISOTOPES
RATS
RODENTS
SACCHARIDES
VERTEBRATES