Positron emission tomography permits noninvasive measurement of regional glucose uptake in vivo in humans. We employed this technique to determine the effect of FFA on glucose uptake in leg, arm, and heart muscles. Six normal men were studied twice under euglycemic hyperinsulinemic (serum insulin -500 pmol/liter) conditions, once during elevation of serum FFA by infusions of heparin and Intralipid (serum FFA 2.0±0.4 mmol/liter), and once during infusion of saline (serum FFA 0.1±0.01 mmol/liter). Regional glucose uptake rates were measured using positron emission tomography-derived 'Ffluoro-2-deoxy-D-glucose kinetics and the three Elevation of plasma FFA decreased whole body glucose uptake by 31±2% (1,960±130 vs. 2,860±250 Mmol/min, P < 0.01, FFA vs. saline study). This decrease was due to inhibition of glucose uptake in the heart by 30±8% (150±33 vs. 200±28 smol/min, P < 0.02), and in skeletal muscles; both when measured in femoral (1,594±261 vs. 2,272±328 Mmol/ min. 25+13%) and arm muscles (1,617±411 to 2,305±517Mmol/min, P < 0.02, 31±6%). Whole body glucose uptake correlated with glucose uptake in femoral (r = 0.75, P < 0.005), and arm muscles (r = 0.69, P < 0.05) but not with glucose uptake in the heart (r = 0.04, NS). These data demonstrate that the glucose-FFA cycle operates in vivo in both heart and skeletal muscles in humans. (J.

Coronary flow reserve is reduced in young men with FH, and, consequently, coronary resistance during hyperemia is increased. The results demonstrate very early impairment of coronary vasomotion in hypercholesterolemic patients.

Aim-To measure the local cerebral metabolic rate for glucose (LCMRGlc) in neonatal brains during maturation using positron emission tomography (PET) and 2-[18F]fluoro-2-deoxy-D-glucose (FDG).Methods-Twenty infants were studied using PET during the neonatal period. The postconceptional age ranged from 32-7 to 603 weeks. All infants had normal neurodevelopment and were normoglycaemic. The development of the infants was carefully evaluated (follow up 12-36 months) clinically, and by using a method based on Geseli Amatruda's developmental diagnosis. LCMRGlc was quantitated using PET derived from FDG kinetics and calculated in the whole brain and for regional brain structures. Results-LCMRGlc for various cortical brain regions and the basal ganglia was low at birth (from 4 to 16 pumol/100 g/minute). In infants 2 months of age and younger LCMRGlc was highest in the sensorimotor cortex, thalamus, and brain stem. By S months, LCMRGlc had increased in the frontal, parietal, temporal, occipital and cerebellar cortical regions. In general, the whole brain LCMRGlc correlated with postconceptional age (r=090; P<0001). The change in the glucose metabolic pattern observed in the neonatal brain reflects the functional maturation of these brain regions. Conclusion-These findings show that LCMRGlc in infants increases with maturation. Accordingly, when LCMRGlc is measured during infancy, the postconceptional age has to be taken into account when interpretating the results.(Arch Dis Child 1996; 74: F153-F157) Keywords: cerebral metabolic rate of glucose, positron emission tomography.

There are no general changes in D2 dopamine receptor Bmax or Kd values in neuroleptic-naive schizophrenics, but there may be a subgroup of patients with aberrant striatal D2 dopamine receptor characteristics in vivo.