Glucose transport and utilization in the human brain: model using carbon-11 methylglucose and positron emission tomography

J Nucl Med. 1986 Dec;27(12):1867-77.

Abstract

3-0-[11C]-Methyl-D-glucose (CMG) is specifically suited for measuring carrier facilitated glucose (G) transport; it enters the free G pool in tissue from where it is not utilized for metabolism in contrast to G, but is transported back into circulation. The ratio of carrier affinity for G and CMG was reported to be 1.11. By simultaneously measuring CMG concentration in plasma and in cerebral cortex in vivo with positron tomography at 1-min intervals for 40 min, two time-activity curves are obtained, as reported previously, which together with the G concentration in plasma yield the in vivo rate constants of G transport across the blood-brain barrier and the rate of G inflow; a repeat measurement at a different G concentration in plasma gives the in vivo Michaelis-Menten constant KM and the maximal rate of transport VMAX. The present paper summarizes and extends this approach to analyzing the free G pool in tissue, the rate of G return to circulation, and the rate of G exit into metabolism with its corresponding rate constants. The data from six volunteers agreed with results reported for the individual biochemical parameters in primate brains.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-O-Methylglucose
  • Blood Glucose / analysis
  • Blood-Brain Barrier
  • Brain / diagnostic imaging
  • Brain / metabolism*
  • Carbon Radioisotopes* / metabolism
  • Glucose / metabolism*
  • Humans
  • Kinetics
  • Mathematics
  • Methylglucosides* / blood
  • Methylglucosides* / metabolism
  • Methylglycosides*
  • Models, Biological
  • Tomography, Emission-Computed*

Substances

  • Blood Glucose
  • Carbon Radioisotopes
  • Methylglucosides
  • Methylglycosides
  • 3-O-Methylglucose
  • Glucose