Long experimental durations are required for double label [14C]- and [3H]2-deoxyglucose autoradiographic methods

Double-label 2-deoxyglucose (2-DG) studies using sequential [14C]- and [3H]2-DG injections demonstrate increased [14C]2-DG uptake during the first and second stimulation periods. To understand why this occurs, the rat mystacial vibrissae were stimulated at various times following [14C]2-DG injection. Local cerebral glucose utilization (LCGU) increased when whisker stimulation was performed at 0-90 min following [14C]2-DG injection. LCGU did not increase when whisker stimulation was performed at 90-150 min following [14C]2-DG injection. To minimize contamination of the two tracers in double label 2-DG mapping studies, the time between [14C]- and [3H]2-DG administration should be increased to 90 min.